Tell us a little bit about what attracted [Edward] Snowden to decide that you were the guy to come to, the kind of reporting that you had been doing in the past.

I had spent several years writing about surveillance issues, so I think, in the first instance, he knew that I would have an understanding of the technological and legal framework in which these issues had to be reported. He knew that I had an understanding of the history of the surveillance debate and the NSA. And I think he also thought that I would be sympathetic to the view that ubiquitous, suspicionless surveillance, when it takes place in the dark, is quite menacing.

But I think the much more prominent reasoning for why he wanted to work with me was not my views on surveillance, but my views on journalism, and specifically my views about the proper role of the media vis-à-vis the state. He was speaking a lot in the beginning about examples where large media outlets such as The New York Times had sat on big stories that were in the public interest, including the famous case in 2004, where [executive editor] Bill Keller decided to suppress the story from Jim Risen and Eric Lichtblau about the NSA because the White House, the Bush White House had asked them to.

He was worried that if he came forward and unraveled his life and risked his liberty, that certain journalists, probably a lot of journalists, would be guided by the views of the government and would suppress a lot of it, or neuter it, or dilute it. And he thought that I would report the story aggressively and wouldn't be overly concerned with how the government viewed it. I think that was critically important to him.

... Tell me the beginnings of how this all started.

I had received, out of the blue, in December 2012, an email from somebody who wrote to me under an anonymous email account. He didn't use his name, and he said, very cryptically and very vaguely, that he had information that he wanted to discuss with me, but could only do so if I were to install encryption. He sort of paid tribute to the importance of communication security and the need to have encryption.

I get emails all the time from people who claim that they have big stories, or information that would make a big impact, so I don't typically just drop what I'm doing to attend to whatever request they're making, because 99 percent of the time it ends up that they're crazy or delusional, or the story is just not very good.

The problem was, we ran into this sort of catch-22, which was he was afraid, with good reason, to say very much to me about what he had or who he was until I had encryption, and I wasn't going to drop what I was doing and install encryption until he could give me some more specific information about why I should prioritize him over all the other things that I was working on at the time.

And we did this little dance for around a month, where I kept telling him that I would install it, and I actually intended to. He kept encouraging me, and then pressuring me to do so. I guess after a month, he realized that it was unlikely to happen, and he became frustrated. And that's when he went to [documentary filmmaker] Laura Poitras with the story and asked her to then get me involved. ...

You get a call from Laura, who you know, and she brings up this idea of going into a partnership on some stories from information from somebody. Do you know it's the same guy that had been trying to talk to you?

No, no. I had no idea. In fact, what happened was, it was in March. I was visiting the United States to give a speech, and she emailed me and said: "It's urgent that I meet with you. Are you going to be in the United States soon?" I just happened to have landed that very day at JFK Airport. We met that night in my hotel, in the lobby, and she showed me these emails that she had been exchanging with this person who was claiming that he was a national security state insider with access to very sensitive information that he believed to be very incriminating, and stated very definitively that he wanted to turn it over to her and to me, to enable us to do the reporting.

I read the emails that Laura and Snowden were exchanging. He was still anonymous at that point. But because she did have encryption, he was much more specific, much more substantive about what he had. It never remotely occurred to me that this was the same person who had been contacting me three months earlier about encryption.

So you soon after that get some documents?

He had said in that email that he needed -- the last email that he had exchanged with her, that he needed roughly six to eight weeks to finalize his preparations and to be able to start providing documents to us. We had no idea what he needed to do. We still didn't know where he worked or who he was.

And true to his word, as usual, it was around six weeks later, maybe a little bit longer, but it was essentially mid-May when I learned from Laura that this was about to happen. And he then contacted me directly.

And he sends you?

Well, it was a little bit strange, because his first priority, when he first contacted me, was he was very much intent on persuading me to travel to Hong Kong to meet him. That was very odd, because we couldn't figure out why somebody with top-level access to national security documents would, of all places, be in Hong Kong. We thought we were going to be in Maryland or Northern Virginia, where people like that typically live and work.

So that raised a little bit of a question mark for me about who this really was, so I said, "Look, I'm definitely willing to travel to Hong Kong, but before I do so, I need to know that it's worthwhile and that you're real."

And he said, "Well, I can send you a very tiny portion of the documents I'd like to give you, the smallest tip of the iceberg." So he did. He sent me around two dozen top-secret NSA documents, one of which was the PRISM program that we ended up publishing, and several other remarkable documents.

These documents come. Take us to that moment. You're reading through that. What are you thinking? What are you seeing? Why is it all of a sudden that you understand that this guy is for real?

It was really shocking to have these documents in my hands, because I had been working on NSA issues for a long time. The problem with it has always been that there has never really been a leak from that agency of any documents. There have been small, mild leaks here and there of some information, but never the actual documents that enable people to really get the evidence about what it is they're doing.

And suddenly in my computer was two dozen extremely sensitive, remarkable documents about very invasive and secretive NSA programs. I could barely believe that I had it. I could hardly breathe at that moment, given how long I had been working on these issues, and felt as though the dam essentially was about to burst.

And I knew, looking at the documents, that they were real. I didn't have any doubt about that. And the fact that I also knew they were the tiniest fraction of what he wanted to give us made me start to realize what the true magnitude of this was.

So the next step, I guess, is the decision to go to Hong Kong. How does that come about? And why, in the end, is it Hong Kong that is the destination?

Well, when someone who is a source of that importance tells you that they want to meet you in Hong Kong, there really isn't that much to think about as a journalist. Your immediate instinct is, "I need to get to Hong Kong as soon as possible." ...

So the first thing I did was contact my editors at The Guardian US in New York, specifically Janine Gibson, who is the editor in chief. ... I got on a plane the next day. I met Laura in New York. We went over together to The Guardian offices. I told her everything that had happened. I reviewed with her the documents I had received, and she essentially said, "You need to go to Hong Kong as soon as possible," which is something I already knew.

So the day after that Laura and I got on the plane, the first plane in the morning -- I think it was 11 a.m. -- and took a 16-hour nonstop flight from JFK to Hong Kong.

So you're on the plane. … Take me there.

Yeah. Right before we got out of the car at JFK, Laura whips out this thumb drive and in a very sort of almost mischievous way says, "Guess what this is," and told me that she had just received a fairly large archive of documents, much, much larger than two dozen. She didn't tell me how many there were, but it was clear it was much larger. ...

The first thing I did, as soon as the plane took off, was started looking through the documents. I didn't sleep one second for the next 16 hours, because the adrenaline made that impossible to do, because I not only saw the magnitude of the documents, just the sheer quantity, the fact that we had in our possession thousands -- not dozens or hundreds -- but many thousands of top-secret NSA documents that were about a wide range of surveillance activities, that came directly from some of the most sensitive areas of the agency.

But it was also the content of what these documents revealed. One of the very first documents that I saw that Snowden had actually flagged in the archive was the court order directing Verizon to turn over to the NSA all phone records of all Americans for both local and international calls. I saw documents that proved that [Director of National Intelligence, James] Clapper had lied, that showed that the NSA was collecting millions and millions of telephone calls and emails, actually billions for each 30-day period from the American telecommunications system. There was more about PRISM and the cooperation between the NSA and the Silicon Valley Industry.

Obviously in 16 hours you can only process so much. It was really just more overwhelming. And every now and then Laura would come up to the front and ask me if I had seen certain documents that had particularly excited her. I showed her certain documents that I had found that I thought were monumental in terms of their impact.

We essentially couldn't believe what it was that we had. And that was really the first time I think I fully understood that this was going to be unlike any story, really ever in American journalism or politics.

Tell me a little bit more about the importance of the Verizon document. What was it [and] why it was so utterly important to understand?

Well, first of all, it had been speculated or whispered or suggested for several years that the NSA was actually collecting the phone records of Americans. But it had never been proven. ...

This, however, was an extremely recent document from, I think, two months earlier. It was an April 2013 court order that confirmed that this was ongoing under the Obama administration. It was the first confirmation that it had ever actually -- that ever emerged that it was happening. ...

What made that document so incredible is that it was incredibly simple in its expression of what it was ordering. It wasn't legalistic; it wasn't complicated. It simply said that Verizon was required to turn over to the NSA the phone records of all Americans. And I don't think Americans really understood that they were under that level of ubiquitous, suspicionless surveillance by an agency that they've always been told focuses on foreign threats and foreign nationals. ...

Why did you think, "This is something I need to report on"? Why was it important?

If you think about, just as an individual, who it is that you call and who calls you, or who you email and who emails you, the people, the list of the people with whom you communicate, it's incredibly invasive for other people to be able to constantly know who it is that you're communicating with, for so many reasons.

And so for the government to simply collect, en masse, and keep and store and be able to analyze at any moment that full list of communications activities that American citizens, suspected of no wrongdoing whatsoever, are engaging in, is really a remarkably invasive and ubiquitous kind of domestic surveillance. …

So you get to Hong Kong. ... What are you supposed to do? How are you supposed to meet him?

... The plan was that we were going to travel to his hotel. He had picked out a part of the hotel that he had said was reasonably remote, so that there wouldn't be a lot of human traffic, as he called it, but not so remote that it would raise suspicions if anyone saw us going there. It was sort of this perfect balance in his mind of where we could meet.

He said that we were to go to this room on the third floor that had a very large green alligator on the floor, which I wasn't sure if that alligator was supposed to be real or was just decorative.

Obviously the question of how would we know who he was when he arrived, because we had still no idea of who he was, what his age was, what his race was, even for certain that he was male. We knew nothing about him demographically at all. So the plan that he picked was that he would be holding a Rubik's Cube in his hand so that when he entered the room, we would immediately know who he was.

So you go there. You see a guy with a Rubik's Cube. What happens?

Well, we had gone to that room, and we waited. And he walked in. The first impression that I had, and that I knew Laura had, was shock at how young he was.

We had both been assuming, although we didn't really discuss it, because it was just an unspoken assumption that he would be older, somebody in his 50s or 60s, in part because we knew he had incredible access to top-secret information, so we assumed he was relatively senior in the agency, but also because there was a real sophistication to his insight and to the way he talked about things, to his strategic reasoning. Also, we knew that he was somebody who was prepared to throw his entire life away. We just assumed that he had been around for so long and gotten so disillusioned that he was willing to do something that extreme.

So when this 29-year-old kid, who looks a lot younger, shows up, it was extremely disorienting and introduced a real awkwardness to our interaction, and kind of a shock.

I think you wrote or said at some point that here was a guy who looked absolutely ordinary, and at the same point, you realized that he was about to change the world. Tell me that sort of sentiment and what you meant.

When we first met, actually a lot of different questions were going through my mind, like did this turn out to be a hoax? Even though I had documents, I still thought maybe there was something very strange about it. Or I thought this was the son of the source, or the assistant of the source, or the gay lover of the source. I mean, I was really trying to get a hold of some kind of explanation that made sense, given my expectations.

We went back to his hotel room immediately. He asked us to go back with him. I think probably within the first two hours, I started becoming increasingly convinced that he was authentic and genuine, that he was who he said he was, that he had the access he claimed, that he was motivated by what he described as his incentives.

That was when I started really focusing on just how remarkable it was that this rather ordinary person, who didn't actually have much position or power, who grew up lower middle class, who didn't even finish high school, had made this unbelievably self-sacrificing and brave choice that was going to have a cataclysmic effect on the world. ...

So take me through a little bit of the six-hour deposition, basically, that you put him through. What was that all about? ...

I had an enormous number of questions, obviously, about who he was and what he had done and why. And I knew that my credibility would be completely dependent upon knowing who he was and making certain that he was who he was claiming to be. ...

Having been a lawyer before I was a journalist, and having been a litigator, and therefore having taken a lot of depositions, the purpose of which is to take somebody's story and just break it down through hours of relentless questioning, where you just ask them similar questions but from different angles and different contexts to ask how reliable those claims are, because if somebody is lying, that process will usually ultimately reveal that, I decided to use those tactics, because I had to be 100 percent certain that I kicked the tires as hard as I could on his story.

The hotel room was relatively small. He sat on his bed. I sat on a chair, probably three feet away from him, maybe four or five feet, and I just looked at him, and I just asked him one question after the next. He didn't go to the bathroom. He didn't eat. He didn't stop and have water. It was really a very rigorous interrogation. I think he later said that it was much more intense than debriefing sessions that he had at the CIA.

I wanted it to be that way by design, because I felt confident that if there was some mendacity or deceit or something scripted, that I would be able to discover it through that process. By the end of that five or six hours, I had zero doubt that he was completely real. I had complete confidence in the fact that I now had this source that I could trust.

And the mood in the room while all this is going on? …

... Definitely we all knew that this was incredibly consequential and risky, that it was super important that we get it right.

But also, there was always this kind of uncertainty, one might even say danger, hovering over the room, especially for the first few days, because we didn't know what the NSA knew about what he was doing. We didn't know what Chinese and Hong Kong, those governments knew about him being there and what he was doing. We didn't know whether the NSA, at any moment, would discover that there was somebody within the agency who had downloaded all these documents and had prepared to then give them to journalists.

So we thought it was very possible that the door could be barged down at any moment and someone could enter to arrest Snowden. There was always that tension compounding all of the other kind of reasons for intensity that always made our interaction in that hotel room very surreal and always quite tense.

And he knows -- I mean, at this point and all the way through, I assume, he understood that he could not remain anonymous. Why is that? ...

From the very first moment that I spoke with him, he was unequivocal about his intention and intent to reveal himself as the source very early on in the reporting. ...

He knew exactly what was going to happen, that he would be charged under the Espionage Act, that he would be declared a traitor, that the U.S. government would likely try and put him in prison for decades, if not for life, and that he would probably never return to the United States again. If he did manage to stay out of their custody, that his girlfriend, his family would be distant, if not gone for the rest of his life. He was very, very thoughtful about not only what would happen, but the reasons why he wanted to do that.

So why? Why do it?

He had said that he viewed the surveillance system that had been constructed, and that he was able to discover and understand as a result of his work inside the agency, as a completely unjustifiable threat to a variety of values that he personally considers to be extremely important, beginning with Internet freedom. ...

He also talked a lot about how personally he evaluates his own worth as a person, and that it isn't enough to simply have noble beliefs and to be opposed to injustices by words or by the operations internally in your brain. He said ultimately, the true test of a person's worth are the actions that they take.

I think that he ultimately decided that the knowledge of living for the rest of his life, viewing himself as somebody who could have stopped this but didn't out of fear, the pain of that, the punishment of that, in his view, was infinitely worse than anything the U.S. government could do to him, including putting him in a cage for the rest of his life. So for him, it ultimately became an easy choice. ...

So for the next two weeks, you guys talk. ... What's going on in those two weeks? What is the routine made up of and sort of the purposes of what's going on?

Well, the three of us developed a trust pretty quickly, so the tension that originally existed from the awkwardness of our interaction dissipated relatively soon.

But still hovering in the air was the knowledge that we were doing things that lots of governments around the world would consider very dangerous or even illegal, as well as the, for me, always sort of dark expectation that within a matter of weeks, this 29-year-old kid for whom I had great admiration was most probably going to end up in the custody of the U.S. government and that at some moment we would never see him again, except on television in an orange jumpsuit and shackles inside of a courtroom, being charged with Espionage Act violations.

So that always hovered over the room, and he had that expectation as well. The priority was to be able to get all the work done together that we needed to get done, before any of that started happening.

And so we always took very extreme precautions to safeguard the confidentiality of our interaction. He would put lots of pillows in front of the door to make sure nobody could overhear what it was we were saying. We would take the batteries out of our cell phone and put them in the freezer, to make sure that they couldn't be used as remote eavesdropping devices. He would often put a blanket over his head when he wanted to enter the computer systems that we had encrypted to prevent overhead cameras from picking up the passwords to the encryption. He basically never left the room out of fear that if he did, someone would physically invade it and put in listening devices.

Everything that we were doing was always based on the premise that there were lots of people who either were monitoring what we were doing, or would soon be monitoring what we were doing. ...

Before we move forward with the chronology, take us to some of what he defined as his bio. I mean, he talked to you about enlisting in 2004. Why is that important to understand about him, why he did it, how he ends up eventually at the CIA and then eventually NSA? ...

There's a little bit of a paradox on the surface, because he grew up in this Virginia community where lots of people who were in the military and the intelligence community lived. His father was in the Coast Guard for 30 years. He has other relatives who work for the federal government.

And then he himself, when he got out of high school, without actually finishing high school, the first thing he did was enlisted in the Army and did special training boot camp in order to go and fight in the Iraq War, and then after that worked on a series of jobs for the CIA and NSA, mostly.

You wonder at first, how can this person who has sort of devoted himself to working for not just the federal government, but the national security state, become so incredibly disillusioned so quickly, in a way that will make them take this extraordinary choice to undermine it, or to shine light on it?

One of the things I realized fairly quickly is that there's an incredible consistency to it on a more profound level, even though it seems superficially paradoxical, which is, when he talked about why he enlisted in the U.S. Army, he said he felt he had an obligation as a person to go and risk his life for what he thought was a noble war in Iraq, to essentially liberate the Iraqi people from tyranny; that he thought his duty as a human being meant that he should go and risk his life to do that, which ultimately ended up being this same formulation, this same paradigm for what led him to risk his life and his liberty to leak all these documents.

And you could see this kind of moralistic strain that permeated everything that he had done, although he shifted how he thought about the U.S. government from thinking it was a noble endeavor to thinking it was actually kind of deceitful and menacing. His personal paradigm for making decisions remains very much constant. …

... So take us through the evolution of him deciding to leak. How does he become disenchanted? What is he finding when he's at the NSA that is concerning him? ...

He actually said that the first time he began entertaining the prospect of being a whistleblower was when he was working as a systems administrator for the CIA in Geneva and had begun to see things that opened his eyes about what the government does. He cited this one example where case officers had recruited a Swiss banker whom they wanted to provide information to the CIA about some of their targets, that they deliberately got him drunk and sort of exploited his weakness for alcohol, let him drive home one night drunk, so that that person was vulnerable and needed the help of the CIA.

That really bothered him. He said he found other things that the CIA were doing that was inconsistent with how he previously viewed the U.S. government and thought it was wrong for the public not to be aware of these things.

He said he ultimately decided not to leak then, for two reasons. One is that he said when you leak CIA documents, you actually can harm people, meaning undercover agents and the like, as opposed to systems, which is what you harm when you leak NSA documents.

But he also said that this was an election year. It was 2008, and he thought that the election of Barack Obama might actually begin to alleviate some of the sharper and more excessive abuses of the intelligence community, given Obama's image and the promises on which he was running.

He said it was pretty soon into 2009 when he realized that, rather than reforming a lot of these practices, that Obama was continuing them and in some cases even making them more extreme.

He said at that moment, he realized that leadership is about going first, not about waiting for other people, like Obama, to save the day and go first. I think that really changed how he viewed the American political system and its prospects for reforming things on its own, as well as what his own individual role in reform efforts ought to be.

After the CIA, he went to work in Japan for NSA and had much greater access to what NSA was doing. He was able to watch real-time surveillance of potential drone victims, people they were targeting. He was able to watch analysts at their desks, watching targets enter each keystroke in their computer, from people whose computers had been taken over by malware, and he really began to understand the true scope of how much the NSA had gotten its hands into the backbone of the Internet.

I think he started realizing then, combined with his evolving views of the U.S. government, that he couldn't in good conscience allow this to remain secret. It probably ended up taking him a couple more years to do, just because of what a deliberative, strategic thinker he is. He doesn't have an impetuous bone in his body.

So I think once he reached the kind of point of no return, where he decided he was going to be a whistleblower, it took a good long time for him to analyze the best way to do that, for him to figure out how he was going to do it, and then what he was going to do once he got it. ...

Thomas Drake and Thomas Tamm cases are things that he is aware of, he looks at. How does he view those cases, especially the Thomas Drake case? ...

Well, I think there were two different levels of how those prior whistleblowers motivated him. It wasn't just Thomas Drake and Thomas Tamm, but also people like then Bradley Manning, now Chelsea Manning, and the entire WikiLeaks project, that began to open his eyes about the power of unauthorized disclosures, the ability to in a sense exploit the U.S. government's own hugeness against them, because the system prevents them from successfully keeping this information secret.

He watched the debate that ensued from the WikiLeaks disclosures, from the Thomas Tamm disclosure of the NSA program of 2005 and 2006. He then went back to and talked a lot about Daniel Ellsberg and the impact that the Pentagon Papers had. I think he got inspired by this line of people who, despite being persecuted in all sorts of ways, kept emerging and coming forward to disclose important information.

But I think also, the reaction of the U.S. government to be so vindictive and aggressive against whistleblowers, to threaten Thomas Drake with decades in prison, prosecute him under the Espionage Act and destroy his life because of his very mild, directed whistleblowing that he did, or to torture a Bradley Manning, essentially, in prison as the U.N. investigation found, and disappear him incognito from the world for three years before he was ever convicted of anything, I think further intensified his view that the United States had become this entity that abused its power.

When you start looking at a government in that light, as something that is willing to go beyond any real limits, to abuse its power, you start to think that the transparency that you're going to bring to them is even more imperative than ever.

So I think both the whistleblowing itself of Thomas Drake and Thomas Tamm, Chelsea Manning, but also the government's reaction to them, all served to inspire and then bolster his resolve.

Also, the fact that, as much as Drake and Tamm put on the line, and how much they suffered for all that, their failure to really create much change -- I mean, how did he view that, and how did that adjust the directions on how he proceeded?

Yeah. Snowden is very strategic and methodical in his thinking. I think he was intent on avoiding some of the mistakes that he thought were made in those prior disclosures that allowed the government to demonize the disclosures or to distract attention from them or to minimize their impact. And essentially, just simply improve on how it was done.

So I think that, you know, ... although he was a huge supporter of WikiLeaks, and remains a huge supporter of WikiLeaks, I think he thought that the disclosures that Manning ended up making outside of a traditional journalistic context, the fact that they were all made more or less at the same time, ended up minimizing their impact, let the government claim that it was irresponsible and reckless, even though it wasn't. I think he wanted strategically to prevent the government from being able to do that in his case. I think in Thomas Tamm's case and Thomas Drake's case, I think he felt like there was so little of it, that the government could easily just kind of dismiss it away.

So this combination of mass leaking with wanting to do it in a journalistic context, where it was reported on one by one in a very vetted way, working with some of the largest and most well-regarded journalistic outlets in the world, was a way of simply trying to perfect the leaking strategy, to maximize the impact, to make it impossible for the government to distract attention away from the substance of the revelations.

... And the other thing that Thomas Drake did was he stayed within the system until the very end. I mean, he went step by step by step without any success. What did that teach Mr. Snowden?

Yeah, you know, he had become very convinced, by this point, that the system was designed to make whistleblowing within the internal structures impossible. He had, at the CIA, on numerous occasions raised concerns about computer security issues, about improprieties, and had always been told the same thing, which was, "That's not your job. That isn't for you to worry about. You don't know the context. You don't know enough to raise these concerns," basically to shut up and go away. ...

So how does he do it? I mean, here you've got this massive amount of documents. He's a contractor at that point. How is he able to do what he does? 

You know, one of the points that I think has been most obscured and overlooked in all of this is that the prime defense of the NSA, when you raise the concern that they had built this incredibly potent, all-invasive system, is that you need not worry about them abusing it, because they have extremely tight controls over how it's used and that analysts can't do things like listen in on their friends or girlfriends or boyfriends or use it against political opponents, because they would obviously know.

And yet here is this relatively low-level analyst, who doesn't even work for the NSA, who was able to access, if you believe the government, 1.7 million documents, download many, many tens of thousands, and walk out of the agency with them, without them having the slightest idea that it was taking place, and for months after admitting that they still have no idea what he actually took. ...

The most damaging to the NSA, and what they say they're doing and why they're doing it, what's the most damaging documents, specific to domestic, that you can flag?

... I think that the most damaging to the NSA was that very first document domestically.

The Verizon one?

Yeah, because they had tried for a long time to tell Americans that the only people who were being targeted with their surveillance were the terrorists or other people planning very bad things.

And what this document revealed is that they don't discriminate, in any way, that way; that the NSA surveillance system is not directed at very bad people or about terrorists. It's directed at the American citizenry and other citizenries around the world, indiscriminately, in bulk.

But it's only metadata, they say, and we don't fish in that pond unless we have a warrant.

Right. So first of all, metadata is not only just as revealing as listening to the content of emails or telephone calls, but actually can be more revealing.

The example I often use is, if you're a woman and you call an abortion clinic and want to make an appointment, if somebody is listening to that call, they'll essentially hear somebody pick up the phone and identify themselves with the generic-sounding name of a clinic. They'll hear the woman make an appointment for 2:00 on Thursday. And then the call will end, and you'll have very little idea about why that call was made, or even to whom it was made.

But if you're collecting the metadata, you will see that this woman calls the abortion clinic, and then calls it repeatedly right before the appointment, probably after, the same as if somebody sees an HIV specialist every three to six months, or calls an alcohol or drug center or suicide hotline, or a journalist who is communicating with a source, or a human rights activist who is communicating with an informant.

You can be incredibly invasive into the most intimate and private aspect of people's lives by collecting metadata -- on top of which the bulk collection of metadata enables all sorts of complex algorithms and other forms of analytical programs that let you create a complete picture of a person's network of friends and associates, of the people with whom those people are communicating, and in essence to view the entire citizenry from a bird's-eye view, that lets you know everything about what it is they're doing, with whom they're doing it. …

... The articles start running. ... What's the reaction? Is it surprising to you? Is it surprising to Snowden? Is it gratifying to Snowden? What's going on? Because you're still with him when the first articles are being put out there.

... That very first week, when we began reporting the stories, beginning with the very first one and then followed it up the next day with the PRISM story, the impact was so extreme, not just in the United States but around the world. ... People were indignant about what the NSA was doing. In the media they hadn't had any idea that this was taking place. It became very apparent, very quickly, that this story was going to be incredibly significant for a long period of time.

I remember being in Hong Kong, and I would do television interviews all night in the Hong Kong night, because that was the day in the United States. And then I would go back to Snowden's room in the mornings so that we could work on stories throughout the Hong Kong day, which was night, and he would always be watching CNN or other American networks that he was able to get, and was incredibly gratified at how consumed the world media was with the debate that we had just provoked. And he was definitely gratified, and I was very gratified being able to watch him be gratified.

The Obama reaction on June 7, where he admits the collection of data, what's the reaction to that?

Well, we knew that what he said in that speech was not only false, but was going to be proven false. He was saying that the NSA isn't listening to the telephone calls or reading the emails of Americans, which is absolutely wrong. It isn't just that the NSA listens to the telephone calls or reads the emails of Americans when they have a warrant from the FISA [Foreign Intelligence Surveillance Act] Court. It's the case that the NSA frequently reads the emails and listens to the phone calls of Americans without any warrant at all.

The whole point of the 2008 FISA law that President Obama voted for, along with huge numbers of Democrats, was essentially to legalize what had been the illegal Bush NSA program, which was about collecting the communications of Americans when they speak internationally, without a warrant. And when that law was passed, officials of the NSA and the Pentagon were very clear that what they would call incidental collection, which is when they target a foreign national but end up collecting the communications of Americans as well, was actually one of the prime purposes of that law, that they would be collecting an enormous number of communications of Americans without a warrant under that law.

There were documents that we had that demonstrated that, that we were able to then publish, that proved that President Obama's claims in that regard were false. ...

... June 9, so Snowden goes public. Take me to that moment a little bit and sort of describe how it happened and the effect.

... You know, we knew that this was going to be an incredibly powerful event, because usually what happens in this case is the source of the story ends up hiding. And they get dug out; their identity does. Then the first that the world hears about them is either by seeing them in handcuffs, as happened with Chelsea Manning, and then the government gets to define them, or having information only that the government wants people to think and have about this person, so that they're demonized from the start.

And we knew that having him appear in his very rational, humble, clean-cut manner, looking essentially like the son of every Midwestern couple in America, coming forward and saying, "I am the person who did this. Here is why I did it. And I did it because I know that it was the right thing to do," was going to have two important effects.

Number one is, it was going to make it extremely difficult to demonize him, because the first thing that everybody would know about Snowden and would hear about him would come from his own words. He got to define himself publicly.

Then the second aspect of it is that there has been this incredible climate of fear that the U.S. government has purposely cultivated, the way they have demonized whistleblowers, prosecuted them at record rates, made clear that even the most directed form of whistleblowing will be punished with great severity.

And also his willingness to come forward in such a fearless and defiant way we knew was going to set the tone for how the story was going to be perceived from that point forward, that we weren't going to be reporting in fear; we weren't going to be hiding; we weren't going to be ashamed of what we did. To the contrary, it was going to be a very kind of, "We did this because it's the right thing to do." And it was done with a sense of conviction and purpose and pride. ...

The last time you saw him, did you know what was about to happen? What was he feeling?

We knew that the minute we unveiled his identity that he was essentially going to have to go into hiding, because the media horde was about to descend onto Hong Kong and would be looking for him. And the U.S. government would certainly be looking for him.

There was definitely a kind of air of sadness over our last meeting, because I had assumed that I would never see him again, and that the next time I saw him, he was going to be in U.S. custody on a television screen.

But what was really the most amazing thing to me the whole time was, even to this day, I have never seen him exhibit an iota of anxiety or nervousness or remorse about what he did. There was such a complete equanimity, a tranquility to him, because he was so convinced that what he had done was right, and was prepared for any outcome that they would do to him, because he knew that it was the right thing to do. ...

Why does he end up in Russia? Why does he go to Russia?

He ended up in Russia for one very simple reason, and that is that the United States government forced him to stay there by preventing him from leaving. His intention, when he went from Hong Kong to Moscow, was to transit through Moscow on his way to Havana, and then take a flight from Havana to the northern part of Latin America, where he would then seek asylum, and had arranged safe passage, both through Moscow and Havana, to get there.

Once he left Hong Kong, when he left Hong Kong, his passport was valid, because he used his passport to exit Hong Kong. And then, before he arrived in Moscow, his passport had been unilaterally revoked by the U.S. government.

At the same time, the U.S. government bullied and pressured Havana, as well as several other states, out of allowing him safe passage. So he could no longer get a ticket and leave Russia, because his passport had been invalidated. At the same time, his ability to travel to places on his way to where he wanted to go had been destroyed by the U.S. government, so he couldn't leave Moscow. He was therefore forced to stay and seek asylum there, which he ultimately got. …

So you're sitting in Rio. This has all gone down. You're seeing what's happening. What are your fears, as far as what this means for you and your ability to move around, and your ability to go to the United States, and what the United States government might do to you, simply because you reported the story?

... It was really once I realized that the United States was not actually going to get Snowden, because he was going to get asylum in Russia, that I think the threat of them targeting me became real for the first time for me, because the national security state depends on being intimidating and thuggish to deter future whistleblowers or other people who bring them unwanted transparency. And the head that they wanted most on the pike was not available to them, because it was being protected in Russia.

So I knew that at some point, they would start to turn their eyes toward me, especially if I continued to just report document after document, story after story, being as defiant as I was being. …

... All this stuff has been published. So has anything changed?

I think a lot has changed. Certainly the way that people perceive Internet freedom and the value of individual privacy has changed drastically. It's at the forefront of political debates around the world. ...

There is domestic reform efforts in virtually every country to limit the type of state surveillance that governments can do. There is enormous pressure from the tech industry applied to the United States government to limit what it is that they do. And then there's obviously an incredibly bipartisan and ideologically diverse coalition in Congress, unlike we've seen on any other issue for a long time, where the most liberal and the most conservative members of the Congress, and everybody in between, are standing together to think about how to impose serious limits on the NSA.

So I think, in terms of the debate around the world, how people think about all these issues, as well as legislative and reform efforts, there's all sorts of things that are unfolding.

Should Americans still be concerned about the NSA and what the NSA is doing?

Absolutely. There's been reform talked about, about the NSA. President Obama gave one of his patented pretty speeches about it, but proposed mostly cosmetic reforms. So it's still this incredibly rogue and unaccountable agency that has the ability to monitor whatever communications they want. And history teaches that, when a system like that is built, it is abused. ...

You've talked to Snowden a lot still. He says he's won. What does he mean by that?

He didn't actually say that he won. He said that his mission was accomplished. What he meant by that was that, as a whistleblower, his mission was to get this information to the public through journalists who would deliver it accurately and responsibly, so that the world would understand what it was that was taking place, and could therefore have an informed and meaningful debate about that. And that's exactly what has happened. ...

And the critics that say, "Hey, guys, remember 9/11? Remember the 3,000 that died? What you're doing is you're tying our hands behind our back; that as much as you think you're doing good to protect the privacy rights of Americans, the other side of that equation is the security of Americans, and what you're doing there is damaging it." What's his response? What's your response to that criticism?

So much of the spying that we revealed has blatantly nothing to do with terrorism, whether it be spying on oil companies in Brazil, such as Petrobras, or spying on economic summits where governments negotiate economic agreements, or spying on U.S. law firms representing Indonesia in trade talks, or directing the spying system at hundreds of millions or billions of people indiscriminately.

Terrorism is the pretext used to justify the system but is not, in fact, its actual purpose as evidenced by the huge amount of spying they do that have nothing to do with that.

The other aspect to it is, that if you were to have a system that actually was about directed spying, targeted spying aimed at terrorists, you could make the case that the system is about stopping terrorist plots. When you collect billions of emails and telephone calls around the world every day indiscriminately, it actually makes it more difficult to stop terrorist plots because you have such a vast amount of information that it's impossible even to know what it is that you had. What the NSA is doing actually makes detecting terrorist plots harder not easier, on top of destroying people's privacy.