Silent Horizon is a United States war exercise that simulates cyberwarfare . It is run by the Central Intelligence Agency , an independent civilian intelligence agency of the United States government . The war exercise was first held in 2005 , and the scenario was five years in the future in which an attack on the same scale as the September 11 attacks takes place and includes hackers hired by anti-American organizations . The Information Operations Center at the CIA ran the war exercise , and around 75 officials , mostly from the CIA , participated in the exercise , reacting to different attacks . The exercise took place in Charlottesville , Virginia . The CIA did not make public its findings . Edward V. Linden , in '' Focus on Terrorism '' , said , " The national security simulation was considered significant because many U.S. counterterrorism experts feel that far-reaching effects from a cyberattack are highly unlikely . " Richard A. Clarke said in 2010 that Silent Horizon has been taking place every year since 2007
September 11 attacks
September 11 attacks
Silent Horizon