Updated 7:05 p.m.
The Senate Intelligence Committee is asking the director of the National Security Agency to declassify some pieces of information in order to better explain how the agency uses telephone and Internet intercept programs revealed in recent news reports to thwart terrorist attacks.
Sen. Dianne Feinstein (D-Calif.), who chairs the intelligence panel, said Tuesday that she asked Gen. Keith B. Alexander, who leads the NSA and U.S. Cyber Command, to declassify the information "so that we can talk about them, because I think they're really helpful."
Feinstein noted in an exchange with reporters that she has already publicly discussed two incidents where the NSA programs helped stop attacks -- in 2009 in New York and Mumbai.
"But there are other things that are also classified that would be helpful since this has all exploded for the American public to know," she said. "If we can get that declassified, we can speak much more clearly."
The Intelligence Committee met Tuesday afternoon with Alexander about the leaks, but virtually all members of the panel stayed silent as they left the meeting.
The committee's ranking Republican, Sen. Saxby Chambliss (Ga.), would only say that Alexander does not know the whereabouts of Edward Snowden, who shared information about the NSA programs with The Washington Post and the Guardian newspaper.
Senior intelligence and Justice Department officials briefed members of the House of Representatives late Tuesday on the NSA's phone-tracking program, according to lawmakers who attended. All members of the House were invited, but it was not clear whether every member attended.
Rep. Cynthia Lummis (R-Wyo.) said the briefing focused on how NSA collects "telephone metadata," or raw information on telephone numbers dialed and the length of calls. But she said she had hoped to learn more about PRISM, the NSA program that allows the agency to gain access to the servers of Internet companies for a wide range of digital data.
Rep. Marsha Blackburn (R-Tenn.) agreed that she learned "not as much as I wanted. I think we have a long way to go on this, but I appreciate that they were willing to give us some information."
Rep. Brad Sherman (D-Calif.) said he asked the officials why the Foreign Intelligence Surveillance Court doesn't hold on to the telephone metadata compiled by the NSA.
"We'd like to believe that everybody always does the right thing and that every part of the Executive Branch can be trusted, and certainly if you have the Justice Department overseeing the NSA that two Executive Branch departments ought to be enough, but I'd like to see the courts in control of the metadata if we're going to have a billion records a day added to the data that's kept on Americans," Sherman said.
Sherman acknowledged that lawmakers have previously approved laws that permit the NSA to collect telephone and Internet records, but said he and other lawmakers didn't realize "that a billion records a day were coming under the control of the NSA and the Executive Branch."
Rep. C.A. "Dutch" Ruppersberger (D-Md.), the ranking Democrat on the House Intelligence Committee, said that the officials sought to answer questions from lawmakers as best they could.
"I think what really came out of it is that we need, as Congress, to move forward from this issue that has occurred and debate the issue," Ruppersberger told reporters after the meeting. "It's a debate between how far we go with public safety and protecting us from terrorist attacks, versus how far we go on the other side and what programs we use with that issue."
A similar briefing for the entire U.S. Senate is scheduled for Thursday. Feinstein said she has invited a judge from the FISA court to attend the briefing and explain how the 11-judge panel reviews NSA requests to continue the telephone tracking program.
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