In 2006, Congress re-confirmed parts of the law, including the telephone and Internet surveillance programs. Both have been used for over five years, and many lawmakers have known about them.

I’m Mario Ritter.

The surveillance programs may have been legal, but they were top-secret. Their existence was known mainly to lawmakers and officials in the National Security Agency and the Federal Bureau of Investigation.

But Edward Snowden is not a lawmaker or government employee. He was a computer technician for private companies. The companies did contract work for the National Security Agency, and Mr. Snowden worked with the agency’s computers. It is not clear how he learned about the surveillance programs. But, he had permission to see top-secret information.

Mr. Snowden told The Guardian that he made public secret documents to protect “basic liberties for people around the world.”

“Over time, the awareness of wrongdoing sort of builds up and you feel compelled to talk about it, and the more you talk about it the more you are ignored, the more you are told it’s not a problem, until eventually you realize that these things need to be determined by the public, not by somebody who was simply hired by the government.”

Shortly before telling the media about the programs, Mr. Snowden left his home in Hawaii and went to Hong Kong. The American has said he hopes Hong Kong will not send him back to the United States for trial.