A top Republican lawmaker claimed Thursday terrorists have already started to change their behavior after a self-described NSA whistleblower leaked information about classified U.S. surveillance programs to various media outlets, saying the leaks may make it "harder to track bad guys."
The chairman of the House Intelligence Committee, Rep. Mike Rogers, R-Mich., declined to provide specifics on what terrorists he was referring to, only saying there are "changes we can already see being made by the folks who wish to do us harm, and our allies harm."
He also said the revelations might "make it harder to track bad guys trying to harm U.S. citizens in the United States."
Former National Security Agency contractor Edward Snowden made headlines worldwide after he leaked information about two NSA programs that collect millions of telephone records and track Internet activity.
Snowden fled to Hong Kong in May and has granted some interviews since then, saying he hopes to stay there and fight any charges that may yet be filed against him.
The ranking Democrat on the committee, Rep. C.A. Dutch Ruppersberger of Maryland, said he's concerned that Snowden fled to Hong Kong because of China's history of spying on the U.S.
"It seems unusual that he would be in China and asking for the protection of the Chinese government ... but we're going to investigate," Ruppersberger said.
Rogers added, "Clearly, we're going to make a thorough scrub of what his China connections are."
Rogers and Ruppersberger spoke to reporters after a closed committee briefing with the NSA's director, Gen. Keith Alexander, who said he hopes to declassify details of dozens of attacks disrupted by the programs. Alexander said officials don't want to "cause another terror attack by giving out too much information."
Officials have thrown out widely varying numbers of the attacks they say the broad surveillance of Americans' phone and online usage has thwarted. On Wednesday, Alexander said dozens have been stopped. Ruppersberger said the surveillance "has thwarted 10 possible terrorist attacks," then amended that number to be in line with Alexander's statement. In the initial days after the disclosures of the programs, officials cited one case.
The disclosures raised privacy concerns as Americans -- some of them members of Congress -- learned for the first time the extent of surveillance powers granted by the secret Foreign Intelligence Surveillance Court to help U.S. intelligence and law enforcement agencies track terrorists.
Investigators have been trying to determine which facilities the 29-year-old Snowden visited during his intelligence career to decide how much classified data he had access to as a computer systems analyst for the NSA and earlier for the CIA, according to two congressional staffers. They spoke on condition of anonymity because they were not authorized to describe the investigation publicly.
"It's clear he attempted to go places he was not authorized to go," within the classified systems, Rogers said. He called Snowden "a fairly low-level individual, but because of his position in the IT system had access to certain pieces of information that, candidly, he did not understand, or had the full scope of what these programs where, who decided on his own he was going to release this information."
FBI Director Robert Mueller defended the programs in testimony to Congress on Thursday. In what is likely his final appearance as FBI director before the House Judiciary Committee, Mueller said that terrorists track leaked information "very, very closely" and that because of leaks "we lose our ability to get their communications" and "we are exceptionally vulnerable."
Rep. John Conyers of Michigan, the Judiciary Committee's ranking Democrat, said, "It's my fear that we are on the verge of becoming a surveillance state."
In defending the programs, Mueller called attention to the run-up to the 2001 terrorist attacks, saying that if the controversial surveillance efforts had been in place back then, they might have uncovered the hijackers' plot. The 9/11 Commission found that among the major U.S. failures before the attack was that agencies didn't share information they already had about suspected terrorists with the FBI.
"If we had had this program, that opportunity would have been there," Mueller said.
"I am not persuaded that that makes it OK to collect every call," Conyers replied.
The Associated Press contributed to this report