What happened
Following the September 11 attacks, the CIA established a network of secret detention facilities in multiple countries, first publicly revealed by the Washington Post in November 2005 and formally acknowledged by Bush in September 2006. The 2014 Senate Intelligence Committee's summary report — 525 pages of a still-classified 6,700-page study — documented the torture or ill-treatment of at least 39 detainees among 119 held in the programme, using techniques including waterboarding, rectal feeding and rehydration without medical necessity, prolonged standing sleep deprivation, and confinement in small dark boxes.
At least three detainees were waterboarded: Abu Zubaydah, Abd al-Rahim al-Nashiri, and Khalid Sheikh Mohammed, the latter 183 times in a single month following his 2003 capture. Zubaydah was held for over four years across multiple black sites, waterboarded, deprived of sleep and solid food, and confined in coffin-like boxes.
In December 2007 the CIA admitted it had destroyed videotapes of the interrogations, recorded in 2002 and destroyed in November 2005 — after congressional and judicial inquiries had already begun seeking exactly that evidence. No senior official responsible for authorising or overseeing the programme was ever criminally prosecuted.