Army Gen. Keith Alexander delivered a forceful defense of spy operations at a rare open hearing on intelligence, revealing that one threat that was thwarted was directed at the New York Stock Exchange.
Alexander said the two recently disclosed programs - one that gathers U.S. phone records and another that is designed to track the use of U.S.-based Internet servers by foreigners with possible links to terrorism - are critical in the terrorism fight. The programs "assist the intelligence community to connect the dots," Alexander told the committee in a rare, open Capitol Hill hearing.
"In recent years, these programs, together with other intelligence, have protected the U.S. and our allies from terrorist threats across the globe," Alexander said.
According to Sean Joyce, deputy director of the Federal Bureau of Investigation, the NSA identified an extremist in Yemen who was in touch with an individual in Kansas City, Mo., in a bomb plot targeting Wall Street.
A terrorist financier inside the U.S. was identified and arrested in October 2007, thanks to a phone record provided by the NSA, Joyce said under questioning. The individual was making phone calls to a known designated terrorist group overseas.
Rep. Mac Thornberry, R-Texas, asked if that country was Somalia, which Joyce confirmed, though he said that U.S. counterterrorist activities in that country are classified.
Edward Snowden, a 29-year-old former contractor with Booz Allen Hamilton, is hiding in Hong Kong after leaking to The Guardian that the U.S. government had collected phone records of millions of Verizon customers. His father went on television Monday urging him not to release any more U.S. secrets.
Leaders of the panel have been outspoken in backing the programs and assailed Snowden's actions as criminal.
The general counsel for the intelligence community said the NSA cannot target phone conversations between callers inside the U.S. - even if one of those callers was someone they were targeted for surveillance when outside the country.
The director of national intelligence's legal chief, Robert S. Litt, said that if the NSA finds it has accidentally gathered a phone call by a target who had traveled into the U.S. without their knowledge, they have to "purge" that from their system. The same goes for an accidental collection of any conversation because of an error.
The Associated Press contributed to this report.