GWEN IFILL: The American public learned a little more today about the sweeping surveillance of telephone communications revealed by Edward Snowden.
The government released heavily redacted documents that showed, broadly, how the National Security Agency uses the data. And, in London, The Guardian newspaper published images of what analysts see, under a program known as XKeyscore.
For more, we turn to Charlie Savage, who's covering the story for The New York Times.
Charlie Savage, because you're covering this story, tell me what new you saw in these documents today.
CHARLIE SAVAGE, The New York Times: Right.
Well, as you said, there were two sets of documents. There was an officially released set of documents that the intelligence community and the Obama administration wanted the public to see. And those concerned this program which has been collecting for years every phone call died or received in the United States.
And then there was an unofficial release of documents they didn't want anyone to see, and that concerns their vast vacuuming -- they being the National Security Agency -- vacuuming up of Internet activity, apparently primarily of foreigners overseas from some 150 different sites scattered around the world.
That would be browsing habits, search terms on Google and other such Web sites, what's being said in encrypted chat sessions and so forth, two very different programs.
GWEN IFILL: Yes. That's the XKeyscore one you're talking about.
Is that something perhaps foreign governments know that we are doing?
CHARLIE SAVAGE: From the document, we can see that the five countries in the sort of Anglosphere, Canada, Britain, New Zealand, Australia, and the United States, must all be participating in this knowingly, but the number of dots where there are collection site servers scattered around the world, including some countries that are not friendly to the United States, suggest that there are countries that didn't know this was happening, and I suspect we will see some reaction around the world as this starts to get digested.
GWEN IFILL: The Obama administration has said since the beginning we're gathering metadata, but we're not actually listening in on phone calls, we're not actually gathering information, unless we have some reason.
Was there anything in either of these two sets of documents today that would undercut that argument?
CHARLIE SAVAGE: Well, again, you have to separate the two of them, and that also goes to the statement that you cited the administration as saying.
When it comes to collecting metadata, calling logs, who called whom inside the United States, yes, by definition that doesn't include content, what was said. Of course, they do wiretap all the time. It's just not through that program. And there's extra rules and court approval for wiretapping inside the United States.
There are essentially no rules for surveillance abroad. The U.S. Constitution doesn't cover non-citizens not on U.S. soil. The domestic wiretapping laws are written to exclude that kind of foreign intelligence collection activity. It's kind of open season. Whatever a country can get away with, it does in the espionage world.
And what we have seen in the last few weeks with all these leaks from Edward Snowden from the NSA is that the United States really can do quite a lot, more even than was long suspected about their capacity to just vacuum up, process and spy on what the world is doing on its telecommunications networks.
GWEN IFILL: What these domestic documents that were released today, that were declassified today showed us is -- confirmed some of the things that the Edward Snowden leaks told us about major phone companies like Verizon turning over documents to the government.
Do we have any idea how widely that -- how much information was gathered and what use the government makes of it?
CHARLIE SAVAGE: Well, so, this is the key question that senators today at the Senate Judiciary Committee hearing and lawmakers generally have been asking about this domestic phone log collection program involving Americans' communications, which is we can see how on paper it's useful.
And you already have the data. It's all in one big set. If you want to go look and see you know, this person is a suspect, who have they been in contact with, who have those people in turn been in contact with, you can very quickly do that if you have already collected the data of everybody. If you have the haystack, you can go searching for the needles.
But the question they keep asking is, has this actually thwarted any plot? We know that the collection overseas appears to have been quite useful. This data that leaked today suggested that 300 terrorists as of 2008 have been identified from this overseas collection, but what about the domestic collection that has these implications for Americans' privacy rights?
And the intelligence community has really struggled to come up with compelling examples of how this is not merely a theoretically useful tool, but one that has actually stopped something from happening that otherwise would have happened.
GWEN IFILL: Are they persuading anybody in the House or the Senate that that is so -- what we saw last week, that the House vote came very close to outlawing this kind of activity. Was there still more skepticism today?
CHARLIE SAVAGE: Certainly, I think most notably today at the Judiciary Committee hearing, the Democratic chairman of that committee, who is a very powerful figure in the Senate, Patrick Leahy, said that he had been looking at a classified list of terrorist events that had been disrupted by various surveillance programs, and that he saw very little on it that suggested that there was utility to this American phone log program.
He said if it doesn't seem to be effective, then it should be shut down, and so far he's not persuaded. And so despite fact that members of the Intelligence Committee -- at least leaders of them -- have been -- who knew about this all along have been trying to defend it and the intelligence community in the Obama administration, a lot of which are career officials who span administrations, have been trying to defend it, we see skepticism, bipartisan skepticism in both chambers of Congress.
GWEN IFILL: Sounds like more shoes yet to drop.
Charlie Savage of The New York Times, thanks for keeping track for us.
CHARLIE SAVAGE: Thank you.