Susan Headley (born 1959, also known as Susy Thunder or Susan Thunder) was a hacker during the late 1970s and early 1980s. A member of the so-called Cyberpunks, Headley specialized in social engineering, a type of hacking which uses pretexting and misrepresentation of oneself in contact with targeted organizations in order to elicit information vital to hacking those organizations.
Born in Altona, Illinois in 1959, Headley claims to have dropped out of school in the eighth grade after a difficult childhood. She later moved to Los Angeles, California where she worked as a prostitute. She met computer hacker Kevin Mitnick (also known as Condor) in 1980, and together with another hacker, Lewis de Payne (also known as Roscoe), formed a gang of phone phreaks.
An offshoot of the original Roscoe Gang, the new group hacked into various network systems based in California, including U.S. Leasing in December 1982 and the Digital Equipment Corporation.
In 1982, Headley testified against Mitnick and de Payne in a theft case related to Pacific Bell telephone company, and she also provided key evidence against de Payne in the U.S. Leasing case. At the time she was working as a RSTS system administrator for American Telecommunications Corp (the makers of the Mickey Mouse Phone) of Los Angeles. She then gave up hacking and eventually moved to Las Vegas, where she became a professional poker player.