Top 10 World Hacker:- 1. Gary McKinnon Gary McKinnon (born 10 February 1966) is a Scottish systems administrator and hacker who was accused in 2002 of perpetrating the "biggest military computer hack of all time," although McKinnon himself states that he was merely looking for evidence of free energy suppression and a cover-up of UFO activity and other technologies potentially useful to the public. On 16 October 2012, after a series of legal proceedings in Britain, Home Secretary Theresa May withdrew her extradition order to the United States. McKinnon was accused of hacking into 97 United States military and NASA computers over a 13-month period between February 2001 and March 2002, at his girlfriend's aunt's house in London,using the name 'Solo'.The US authorities stated he deleted critical files from operating systems, which shut down the United States Army’s Military District of Washington network of 2,000 computers for 24 hours.