He has been identified as 29-year-old Edward Snowden, a former technical assistant for the CIA and current employee of defense contractor Booz Allen Hamilton.
The British newspaper, The Guardian, revealed his identity at his request.
"My sole motive is to inform the public as to that which is done in their name and that which is done against them," Snowden told the newspaper.
Snowden is responsible for exposing two secret spy programs, one in which the NSA was allowed collect the phone records of millions of Americans. The Obama administration has since said the NSA program doesn't listen to actual conversation.
A second Internet scouring program called Prism was also exposed in the stories in The Guardian. Prism allowed the NSA and FBI to monitor the online activities of people overseas.
Snowden said the programs are not secure.
"Any analyst at any time can target anyone. Any selector. Anywhere. Where those communications will be picked up depends on the range of those sensor networks and the authority that that analyst is empowered with," Snowden said, in accompanying video on the Guardian's website. "Not all analysts have the power to target anything. But I, sitting at my desk, had the authority to wiretap anyone, from you or your accountant to a federal judge to even the president if I had a personal email."
The NSA has filed a criminal report with the U.S. Justice Department in relation to the leaks.
According to The Guardian, Snowden is currently in Hong Kong. He risks prosecution by the U.S. government.
The Associated Press contributed to this report.