The leaker and the leaks: 5 things to note about NSA surveillance programs

National Security Agency plaques are seen at the compound at Fort Meade, Md., June 6, 2013. (AP / Patrick Semansky)

WASHINGTON -- Edward Snowden identified himself Sunday as a principal source behind revelations about the National Security Agency's sweeping phone and Internet surveillance programs. Five things to know about the disclosures:

- THE PROGRAMS: The NSA has been collecting the phone records of hundreds of millions of Americans each day, creating a database through which it can learn whether terror suspects have been in contact with people in the U.S. While the NSA program does not listen to actual conversations, the revelation of the program reopened the post-Sept. 11 debate about privacy concerns versus heightened measures to protect against terrorist attacks. Separately, an Internet scouring program, code-named PRISM, allows the NSA and FBI to tap directly into nine U.S. Internet companies to gather all Internet usage - audio, video, photographs, emails and searches. The effort is designed to detect suspicious behavior that begins overseas.

- THE LEAKER: A 29-year-old high school dropout who worked for consulting giant Booz Allen Hamilton has claimed responsibility for disclosing the programs to The Guardian and The Washington Post. Snowden told The Guardian that he enlisted in the Army, was dismissed after breaking both legs during a training exercise and later got a job as a security guard at a covert intelligence facility in Maryland. He says he later joined the CIA and was posted under diplomatic cover in Geneva, Switzerland. He later worked for consulting companies and claims he spent four years working as a contractor with the NSA. In a statement, Booz Allen Hamilton said he has worked for them less than three months.

- THE REASON: In interviews with The Guardian and the Washington Post, Snowden said he felt compelled to disclose the program because he wanted "to inform the public as to that which is done in their name and that which is done against them." Snowden says he also was disillusioned with CIA tactics to recruit spies in Geneva and was disappointed President Barack Obama did not do more to curtail surveillance programs after his 2008 election.

- THE REACTION: The government's response was fierce. Director of National Intelligence James Clapper said the disclosures were "gut-wrenching to see this happen because of the huge, grave damage it does to our intelligence capabilities" and asked the Justice Department to investigate. Rep. Mike Rogers, the Republican chairman of the House Intelligence Committee, said the journalists who reported on the programs don't "have a clue how this thing works; neither did the person who released just enough information to literally be dangerous." Democratic Sen. Dianne Feinstein, the chair of the Senate Intelligence Committee, said she wanted to see the leaker prosecuted. Rep. Peter King, a Republican on the intelligence panel, called for Snowden to be "extradited from Hong Kong immediately." John Negroponte, a former director of national intelligence, called it "an outright case of betrayal of confidences and a violation of his nondisclosure agreement." Yet some also said Snowden's revelations should spark a debate about the secret programs and civil liberties. "I am not happy that we've had leaks and these leaks are concerning, but I think it's an opportunity now to have a discussion about the limits of surveillance, how we create transparency, and above all, how we protect Americans' privacy," said Sen. Mark Udall, D-Colo.

- THE CONSEQUENCES: The NSA has asked the Justice Department to open a criminal investigation, and Snowden could face decades in prison if convicted on espionage or treason charges. The Obama administration has been particularly aggressive in prosecuting those who disclose classified information. Snowden has fled to Hong Kong, a former British colony that is now a semi-autonomous region of China. Snowden says he chose the city because he expects leaders could resist pressure from the U.S. government. Snowden also says he would "ask for asylum from any countries that believe in free speech and oppose the victimization of global privacy." Hong Kong has an extradition treaty with the United States that took force in 1998, according to the U.S. State Department website.

Some other famous leakers in recent history

Edward Snowden, a 29-year-old American intelligence analyst, has revealed himself as the source who disclosed the U.S. government's secret phone and Internet surveillance programs. Some other famous leakers in recent history:

DANIEL ELLSBERG: A military analyst, he passed the Pentagon Papers -- a secret Defence Department study of U.S. involvement in Vietnam -- on to The New York Times and other newspapers in 1971.

W. MARK FELT: An associate director at the FBI, he was Deep Throat, the source who gave information about Watergate to The Washington Post in the 1970s. He unmasked himself in 2005.

MORDECHAI VANUNU: He was an Israeli nuclear technician in 1986 when he revealed Israel's nuclear weapons program. He served 18 years in prison.

FREDERIC WHITEHURST: Beginning in 1992, the FBI agent exposed shoddy work and inaccurate testimony from the bureau's crime lab.

JEFFREY WIGAND: A Brown & Williamson tobacco executive, he co-operated with CBS television news magazine ' "60 Minutes" and the Food and Drug Administration in the 1990s in exposing cigarette manufacturers' practices.

BRADLEY MANNING: The U.S. Army private gave a trove of classified military and diplomatic material to WikiLeaks. His court-martial is underway at Fort Meade, Maryland.