Edward Snowden, a former American intelligence contractor who exposed the U.S. government's secret surveillance programs, claims he was trained as a spy by the government in a new interview with NBC News. Take a look at some other famous leakers/whistleblowers in recent history:
Daniel Ellsberg -- This State Department employee leaked the Pentagon Papers, a secret Defense Department study of how the United States came to fight the Vietnam War, to The New York Times and other newspapers in 1971.
W. Mark Felt -- Otherwise known as "Deep Throat," this associate director at the FBI leaked information about Watergate to Washington Post reportersBob Woodward and Carl Bernstein in the 1970s. He revealed his identity in 2005.
Mark Whitacre -- He worked with the FBI in 1990s to expose price-fixing in agriculture by his own company, Archer Daniels Midland, but ended up in legal trouble himself. Whitacre was played by Matt Damon in the 2009 movie "The Informant!"
Mordechai Vanunu -- This former Israeli nuclear technician revealed details of Israel's nuclear weapons program to the British press in 1986.
Sherron Watkins -- Her internal memo about accounting irregularities at Enron proved that executives knew of illegal activities in their midst and is considered key in facilitating the energy giant's downfall in 2001.
Coleen Rowley -- An FBI agent, she alleged in 2002 that the agency had failed to act on information about one of the key figures in the 9/11 terrorist attacks, Zacarias Moussaoui. She was named Time's "Person of the Year" in 2002 along with two other female whistleblowers.
Erin Brockovich -- As a law clerk without any real legal training, she uncovered a series of mysterious illnesses in the town of Hinckley, Calif., linked to wastewater from a nearby Pacific Gas & Electric plant. Julia Roberts starred in the 2000 movie about her, "Erin Brockovich."
Frank Serpico -- A New York City police officer, he attempted to confront the rampant corruption within the police department in 1971. He left the force after being shot in the face during a botched drug raid and later moved out of the country. Al Pacino played him in the 1973 movie "Serpico."
Frederic Whitehurst -- An FBI agent, he exposed shoddy work and inaccurate testimony from the bureau's crime lab beginning in 1992.
Jeffrey Wigand -- This former tobacco company executive made enemies by claiming on "60 Minutes" in 1996 that cigarette companies knew their products contained addictive levels of nicotine. He was played by Russell Crowe in the 1999 film "The Insider."
Julian Assange -- A hacker as a teenager and former computer programmer, he's best known as the founder and editor-in-chief of WikiLeaks, which publishes secret information, news leaks and classified documents submitted by anonymous news sources and whistleblowers. He's currently wanted for questioning in a sex assault investigation and has been living in the Ecuadorian embassy in London since June 2012.
Karen Silkwood -- This young mother of three died mysteriously in 1974 during her campaign to document lax safety regulations at the Kerr-McGee nuclear facility. She was played by Meryl Streep in the 1983 film "Silkwood."
Linda Tripp -- This former White House staff member was a key figure in the Monica Lewinsky scandal that led to an attempt to remove President Bill Clinton from office during his second term.
Bradley Manning -- A U.S. Army private, he provided classified military and diplomatic material to Assange's WikiLeaks site. He was convicted of espionage charges, but acquitted of the more serious charge of aiding the enemy following a court-martial.
Crystal Lee Sutton -- The inspiration for the 1979 movie "Norma Rae" starring Sally Field, she fronted efforts to unionize workers at the North Carolina textile factory she worked at. She and other workers were paid just $2.65 an hour for folding towels in poor working conditions.