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GEORGE STEPHANOPOULOS: Hello again. The secret struggle to balance national security and individual liberty broke out into the open this week after a series of blockbuster revelations starting in the Guardian newspaper. We learned that the government has the capacity to track virtually every American phone call and to scoop up impossibly vast quantities of data across the Internet. And our first guest is the Guardian columnist getting these scoops, Glenn Greenwald. Thank you for joining us today, Mr. Greenwald. You are really on a roll. You broke another story yesterday showing the scale of the data collection programs. In March 2013 you report the government collected 97 billion pieces of data, almost all of it from outside the U.S. What's the key finding here?

GLENN GREENWALD: There are two key findings. One is that there are members of the Congress who have responsibility for oversight, for checking the people who run this vast, secret apparatus of spying to make sure they're not abusing their power. These people in Congress have continuously asked for the NSA to provide basic information about how many Americans they're spying on, how many conversations in telephone and chats of Americans they're intercepting. And the NSA continuously tells them, we don't have the capability to tell you that, to even give you rough estimates.

And what these documents that we published show, that were marked "Top Secret" to prevent the American people from learning about them, was that the NSA keeps extremely precise statistics, all the data that the senators have asked for that the NSA has falsely claimed doesn't exist. And the other thing that it does, as you said is it indicates just how vast and massive the NSA is in terms of sweeping up all forms of communication around the globe, including domestically.

GS: You also drew new criticism yesterday from the Director of National Intelligence, James Clapper. He called the disclosures "reckless," said the rush to publish this creates significant misimpressions, and added that the articles are filled with inaccuracies. Your response to that?

GG: Every single time any major media outlet reports on something that the government is hiding, that political officials don't want people to know, such as the fact that they're collecting the phone records of all Americans, regardless of any suspicion of wrongdoing, the people in power do exactly the same thing. They attack the media as the messenger, and they try and discredit the story. This has been going back decades, ever since the Pentagon Papers were released by The New York Times and political officials said you're endangering national security.

The only thing we've endangered is the reputation of the people in power who are building this massive spying apparatus without any accountability, who are trying to hide from the American people what it is that they're doing. There's no national security harm from letting people know that they're collecting all phone records, that they're tapping into the Internet, that they're planning massive cyberattacks, both foreign and even domestic. These are things that the American people have a right to know. The only thing being damaged is the credibility of political officials and the way that they exercise power in the dark.

GS: Well, one of the things you reported is that the government has, quote, "direct access" to the servers of massive Internet firms like Google and Microsoft and Facebook, and all the companies have come out and denied it. You see Google saying, "The U.S. government does not have direct access or a backdoor to the information stored in our data centers," similar statements from Facebook and Apple. And Mr. Clapper also said the U.S. government does not unilaterally obtain information. Now, I take it there could be some semantic word games being played here. What's your understanding about what is actually happening? Because it does appear that they don't have direct access to the servers.

GG: Well, our story was very clear. What we said was that, and we presented it as the story from the start, was that we have top secret NSA documents that claim that there is a new program called the PRISM program in place since 2007 that provides, in the words of the NSA's own documents, collection directly from the servers of these companies. We then went to all of those companies named, and they said, no, we don't provide direct access to our servers. So there was a conflict, which was what we reported, that the NSA claims that they have direct access; the companies deny it.

Clearly there are all kinds of negotiations taking place and all kinds of agreements that have been reached between these Internet companies that store massive amounts of communication data about people around the world and the government. We should have this debate out in the open. Let these companies that collect massive amounts of information about people and the government resolve this discrepancy in public. Tell us what it is exactly that these companies are turning over to the government, and what kinds of capabilities the government is wanting to access. So we reported these discrepancies precisely because we want them, those parties, to resolve it in public, in sunlight, and let people decide whether or not that's the kind of country they want to live in when the government can get this massive amount of information.

GS: The DNI spokesman also said that a crimes report has been filed by the National Security Agency. Have you been contacted by the FBI or any federal law enforcement official yet?

GG: No. And any time they would like to speak to me, I'll be more than happy to speak to them, and I will tell them that there's this thing called the Constitution, in the very first amendment of which guarantees a free press. As an American citizen I have every right, and even the obligation as a journalist, to tell my fellow citizens and our readers what it is that the government is doing that they don't want people in the United States to know about. And I'm happy to talk to them at any time. And the attempt to intimidate journalists and sources with these constant threats of investigation aren't going to work.

GS: You've described your source as a reader of yours who trusted how you would handle the material. The source has also been described as a career government official who is concerned about these programs. A former prosecutor called the source a "double agent."

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