Ghost detainee is a term used in the executive branch of the United States government to designate a person held in a detention center, whose identity has been hidden by keeping them unregistered and therefore anonymous. Such uses arose as the Bush administration initiated the War on Terror following the 9/11 attacks of 2001 in the United States. As documented in the 2004 Taguba Report, it was used in the same manner by United States officials and contractors of the Joint Interrogation and Debriefing Center at the Abu Ghraib prison in Iraq in 2003–2004. According to the Swiss senator Dick Marty's memorandum on "alleged detention in Council of Europe states", the U.S. Central Intelligence Agency (CIA) has captured about one hundred persons on European territory and subsequently rendered them to countries where they may have been tortured. This number of one hundred extraordinarily rendered persons is in addition to the estimated hundred U.S. ghost detainees. Secret CIA prisons According to then-CIA chief Michael Hayden in 2007, the CIA had detained up to 100 people at secret facilities abroad (known as black sites) since the 2002 capture of the suspected Al Qaeda operative Abu Zubaydah. One example is Khalid El-Masri, a German citizen abducted by the CIA in Macedonia in January 2004. He was taken to a CIA black site in Afghanistan, known as the Salt Pit, for questioning under 'enhanced interrogation techniques' before he was determined to be innocent in March and eventually released in May 2004 after some additional delays. His abduction was said to be a case of mistaken identity. Germany initially claimed that it did not know of el-Masri's abduction until his return to the country in May 2004. But, on June 1, 2006, the BND (German intelligence agency) declared that it had known of El-Masri's seizure 16 months before Germany was officially informed of his arrest. In a 2007 report, Human Rights Watch related the claims of an alleged ghost detainee, Marwan Jabour, a Palestinian who was arrested in Lahore, Pakistan, in May 2004. He claimed to have been held for more than a month in a secret detention facility operated by Pakistanis and Americans in Islamabad. He was flown to a CIA prison in Afghanistan, where he was held in secret, incommunicado detention for more than two years. During his ordeal, he was tortured, beaten, forced to stay awake for days, and kept naked and