Markus Hess, a German citizen, was a computer prodigy and particularly effective hacker. Hess was recruited by the KGB to be an international spy with the objective of securing U.S. military information for the Soviets.
His exploits are erroneously cataloged and mis-portrayed in the book "The Cuckoo's Egg" by Clifford Stoll.
It is rumored that he was assisted and was not actually the master mind behind the EMACS hole that eventually brought him to court.
http://en.wikipedia.org/wiki/Markus_Hess
http://phrack.org/issues.html?issue=31&id=2