John Kiriakou

John Kiriakou
Near the end of 2012, Greek-American John Kiriakou pleaded guilty to identifying a fellow Central Intelligence Agency officer whose identity was supposed to remain secret. He served a prison sentence of 30 months, and the identity of the C.I.A. officer was never published. Before this illegal act, however, he became famous for blowing the whistle on the C.I.A.'s torture methods, revealing that they commonly used waterboarding against Al-Qaeda prisoners. He disclosed to ABC News that he had heard that waterboarding was briefly used to extract answers from Abu Zubaydah, a suspected aid to Osama bin Laden, leader of Al-Qaeda.