Snowden's leak, he said, revealed details of electronic surveillance programs operating within the law, authorized by Congress and overseen by a federal court. One program related to the NSA's gathering of records of customers of U.S. telephone companies for counterterrorism purposes. Another involves the NSA's collection of the communications of foreigners through U.S. Internet companies.
Snowden said he was motivated by his belief that the government, particularly the ultra-secret NSA, had built an enterprise "that allows it to intercept almost everything" in a way that violates privacy rights.
His revelations of the inner workings of the two programs have reignited a debate over whether the government's secret surveillance programs are sufficiently protective of civil liberties and privacy in the name of protecting the country against terrorism.
Since the attacks of Sept. 11, 2001, the NSA has been at the forefront in collecting electronic information worldwide as part of the nation's counterterrorism efforts. The material exposed by Snowden provided an unprecedented look at the scope of the surveillance carried out by the agency. President Barack Obama defended the surveillance as essential to U.S. security and said he welcomes an extended debate.
"As far as I'm able to judge, the public policy value [of his leaks] far exceeds the potential risk involved to national security," said Steven Aftergood, director of the Federation of American Scientists' Project on Government Secrecy. "It has triggered an intense public debate. These stories have really enriched public discourse."
Aftergood said Snowden's leaks were targeted and selective, unlike those of Army Pfc. Bradley Manning, the former Army intelligence analyst on trial for orchestrating the leak of more than 700,000 government documents to the anti-secrecy WikiLeaks Web site.
"There were lots of records put out by WikiLeaks that had no particular significance other than the fact that they are restricted," Aftergood said. "It was an anti-secrecy campaign. This [Snowden's action] seemed to aim at a much larger target — namely the scope of intelligence surveillance activity and government overreaching and violation of policy."