John Walker was the founder of Autodesk, Inc. and co-author of AutoCAD. After making his millions, Walker went into semi-retirement as a well financed hacker. His later hackerish work is freely available at and includes demoronizer and eat watch.
John Walker is also the name of a famous American Navy turncoat spy. He was recruited by the Soviets in 1967 and sold top secret encryption codes to the Soviet Union for nearly 20 years. He recruited a spy ring that included his own son.

Editors Note:

John A. Walker, the spy, died August 29, 2014, while still in prison. He would have been released in less than nine months.