Gary McKinnon hacked nearly 100 American military and NASA servers from February 2001 to March 2002. What's even crazier is he did it all from his girlfriend’s aunt’s house in London. He managed to delete sensitive data, software, and files, and the U.S. government spent over $700,000 to recover from the damage. He taunted the military while he was at it, posting this message to their website: “Your security system is crap. I am Solo. I will continue to disrupt at the highest levels.”
McKinnon is an interesting guy. He's said his main inspiration for the attack was The Hacker's Handbook by Hugo Cornwall. While hacking NASA, he purposely looked for files that contained evidence of extraterrestrials. He told Wired in 2006 that he found them, too. "A NASA photographic expert said that there was a Building 8 at Johnson Space Center where they regularly airbrushed out images of UFOs from the high-resolution satellite imaging," he said. "I logged on to NASA and was able to access this department. They had huge, high-resolution images stored in their picture files. They had filtered and unfiltered, or processed and unprocessed, files." He currently still lives in Britain.