We do begin with the breaking news, the whistle-blower revealed. The 29-year-old who le the top-secret details of the government's sweeping surveillance program has come forward. He's edward snowden.... See More
We do begin with the breaking news, the whistle-blower revealed. The 29-year-old who le the top-secret details of the government's sweeping surveillance program has come forward. He's edward snowden. He worked with the national security agency, a contract worker, who says he found the extent of the surveillance program, quote, horrifying. He accepts the risk and may never see his home again. We have team coverage this evening, waiting for word from the white house. We b with abc's chief investigative correspondent, brian ross in our washington bureau. Brian, good evening. Reporter: Good evening, david. The person responsible for one of the greatest national security leaks in recent american history faces almost certain criminal prosecution. But he apparently insisted that his identity be made public after fleeing the country for hong kong three weeks ago. My name's ed snowden. I'm 29 years old. Reporter: Snowden said he is a former cia technician, who currently is a civilian contractor with the nsa in hawaii. When you see everything, you see them on a more frequent basis. And you recognize that some of these things are actually abuses. Reporter: Snowden revealed himself and his motivation sunday afternoon in this interview, posted online by "the guardian" newspaper, conducted by columnist glenn greenwald in hong kong. This is the truth. This is what's happening. You should decide if we should be doing this. Reporter: Snowden said he saw firsthand and became increasingly concerned about the reach of the nsa's surveillance of innocent americans. Even if you're doing nothing wrong, you're being watched and recorded. Reporter: That's why he said he chose to expose secret u.S. Programs that collect the phone records of americans. And monitor overseas internet e-mails. I, sitting at my desk, had the authority to wiretap anyone, from you or your account, to a federal judge to even the president if I had a personal e-mail. Reporter: Hours before snowden went public, the chairs of the house and senate intelligence committees both called for the prosecution of the whistle-blower on the abc news program "this week." It's dangerous to us. It's dangerous for national security. And it violates the oath of which that person took. I think they should be prosecuted. You, too, senator feinstein? I do. Reporter: Snowden said he went to hong kong because its history of allowing free speech. "The guardian" reported snowden might try to seek asylum in iceland, to avoid the u.S. Coming after him. You can't come forward against the world's most powerful intelligence agencies and be completely free from risk because they're such powerful adversaries. No one can meaningfully oppose them. Reporter: Asked what he expected to happen to him next, snowden said, nothing good. Adding, I do not expect to see home again.
This transcript has been automatically generated and may not be 100% accurate.