Shaffer alleged that the U.S.
Defense Intelligence Agency (DIA) failed to properly pass on intelligence on 9/11 hijacker
Mohamed Atta. Shaffer's allegations subsequently became known as the
Able Danger controversy. In October 2003 Shaffer told the
9/11 Commission staff director,
Philip D. Zelikow, that in 2000, a DIA data-mining program known as Able Danger had uncovered two of the three terrorist cells which the FBI determined committed 9/11. Shaffer reportedly told Zelikow that DIA leadership declined to share this information with the
FBI because military lawyers expressed concerns about the legality of doing so. Shaffer also asserted that he briefed
Director of Central Intelligence George Tenet on three separate occasions regarding his unit's activities. The
9/11 Commission Report did not mention Shaffer's allegations, but in 2005 and 2006, the chairman of the House Select Intelligence Committee, Rep.
Curt Weldon, publicized Shaffer's
allegations in public statements and hearings. On December 22, 2006, a 16-month investigation by the Senate Intelligence Committee concluded that Able Danger, "did not identify Mohamed Atta or any other 9/11 hijacker at any time prior to September 11, 2001". The
Defense Department's inspector general (DoD OIG) came to a similar conclusion. While Shaffer was stripped of his security clearance, and placed on indefinite unpaid suspension, the investigation of the Defense Department's inspector general concluded that "DIA officials did not reprise against LTC Shaffer, in either his civilian or military capacity, for making disclosures regarding Able Danger". Investigations by both the Defense Department's inspector general and the Senate Intelligence Committee concluded that Able Danger did not identify any 9/11 hijacker before September 11, 2001. ==Censored memoirs==