Edward Snowden, an NSA contractor employee, says he is the source of NSA leaks

to some of the methods used by the CIA to lean on people to provide information to the U.S. government.

“Much of what I saw in Geneva really disillusioned me about how my government functions and what its impact is in the world,” he told the Guardian. “I realized that I was part of something that was doing far more harm than good.”

He felt more hopeful, he said, the following year, when Barack Obama was elected president – but soon realized that the Obama administration was bent on expanding, rather than limiting, the counter-terrorism surveillance projects launched by the George W. Bush administration after the 9/11 attacks.

In 2009 he left the CIA to join Booz Allen Hamilton, where he was able to gain an even deeper understanding of the vast surveillance program the U.S. intelligence community was developing.

It was then, he said, that he “watched as Obama advanced the very policies that I thought would be reined in”, and as a result, “I got hardened.”

He says that over the next three years, he learned just how all-consuming the NSA’s surveillance activities were, claiming “they are intent on making every conversation and every form of behavior in the world known to them.”

He said that once he concluded that the NSA’s surveillance scheme would soon be irrevocable, it was just a matter of time before he chose to act. “What they’re doing” poses “an existential threat to democracy,” he said.

Snowden said he acted on principle. “The government has granted itself power it is not entitled to. There is no public oversight. The result is people like myself have the latitude to go further than they are allowed to,” he said.

Snowden told the newspaper that he admires both Daniel Ellsberg, whom leaked the Pentagon Papers in1971, and Bradley Manning, who was the source for the Wikileaks disclosures. Snowden argues, though, that there is one important distinction between himself and the army private, whose trial began the week Snowden’s leaks began to make news.

“I carefully evaluated every single document I disclosed to ensure that each was legitimately in the public interest,” he said. “There are all sorts of documents that would have made a big impact that I didn’t turn over, because harming people isn’t my goal. Transparency is.”

He said he purposely chose to give the documents to journalists whose judgment he trusted about what should be public and what should remain concealed.

He says his best hope is asylum, with Iceland, reputable as a champion of Internet freedom, at the top of his list.

He is content with the intense political debate already engendered by just the first installment of the disclosures. “I feel satisfied that this was all worth it. I have no regrets.”

Snowden told the Washington Post that he hopes the NSA surveillance programs would now be open to legal challenge for the first time. The Post notes that earlier this year, in Amnesty International v. Clapper, the Supreme Court dismissed a lawsuit against the mass collection of phone records because the plaintiffs could not prove exactly what the program did or that they were personally subject to surveillance.

“The government can’t reasonably assert the state secrets privilege for a program it has acknowledged. The courts can now allow challenges to be heard on that basis,” Snowden said.