STEVE INSKEEP, HOST:
The president's administration has plenty to occupy it here at home. The director of the National Security Agency was on Capitol Hill yesterday, defending the surveillance program that's received so much attention in recent in recent days. General Keith Alexander told the House Intelligence Committee that the NSA programs in question have stopped dozens of terrorist attacks, here and abroad. Here's NPR's Ailsa Chang.
AILSA CHANG, BYLINE: Here was the contradiction on Tuesday. The government wanted to make the case that its secret surveillance programs were the crucial key to stopping lots of terrorists. But giving credit to any one spy program ignored a basic reality: FBI Deputy Director Sean Joyce says you actually have to connect so many, many different dots to catch a terrorist.
SEAN JOYCE: And I think you ask and almost impossible question, to say how important each dot was.
CHANG: But with the public demanding to know why these programs are necessary, the government came up with a list to show it's been up to some truly successful spying. General Keith Alexander, director of the National Security Agency, said the surveillance programs in question have prevented more than 50 terrorism events in more than 20 countries around the world, and the vast majority of that success came from the Internet monitoring.
GENERAL KEITH ALEXANDER: FAA 702 contributed in over 90 percent of these cases. At least 10 of these events included homeland-based threats.
CHANG: Lawmakers are supposed to get a classified list of those 50-some terrorism cases today. So far, the general public has only been getting a small slice of the details. Intelligence officials already disclosed the program's helped catch Najibullah Zazi who planned to blow up the New York City subway system. And then, there was David Headley, who was involved in the 2008 Mumbai attacks.
On Tuesday, the government added two more cases to the mix. Phone records lead them to a San Diego man who tried helping Al-Shabaab. And Internet monitoring helped nab a Kansas City man who conspired to bomb the New York Stock Exchange. Here's Republican Mac Thornberry of Texas talking to Joyce.
REPRESENTATIVE MAC THORNBERRY: Would you say that their intention to blow up the New York Stock Exchange was a serious plot, or is this something that they kind of dreamed about, you know, talking among their buddies?
JOYCE: I think the jury considered it serious since they were all convicted.
CHANG: The hearing was also a way to reassure a jittery public that these surveillance programs had strict constraints. Intelligence officials emphasized the layers of oversight, from a special court to Congress that gets periodic updates on these programs. And then, Deputy Attorney General James Cole kept reiterating they couldn't listen in on phone calls or read the emails of anyone, unless the person was a non-U.S. citizen who was physically outside the U.S.
JAMES COLE: If they make a call to inside the United States, that can be collected, but it's only because the target of that call outside of the United States initiated that call and went there. If the calls are wholly within the United States, we cannot collect them.
CHANG: As for the so-called phone metadata, NSA Deputy Director John Inglis says in all of last year, the government looked up records for fewer than 300 phone numbers. What he suggested was a modest figure. House Intelligence Committee Chair Mike Rogers also helped show the database itself contains no names.
UNIDENTIFIED MAN: Describe the - it's not a - you don't put in a name.
REPRESENTATIVE MIKE ROGERS: We do not, sir. Since the only thing we get from the providers are numbers, the only thing that we could possibly then bounce against that data set are numbers themselves.
UNIDENTIFIED MAN: All right. So there are no names and no addresses affiliated with these phone numbers.
ROGERS: No, there are not, sir.
CHANG: And Inglis says that database can only be queried if there's first a reasonable, specific suspicion that a phone number has terrorism connections. And for any phone customer out there who still thinks his Fourth Amendment rights are being violated, the government says court rulings hold there's no expectation of privacy in who you call or when you call. Ailsa Chang, NPR News, the Capitol. Transcript provided by NPR, Copyright NPR.