Computer expert Clifford Stoll. When Stoll discovered a 75-cent accounting discrepancy in his work as systems manager at Lawrence Berkeley Laboratory, he thought the intruder was a student prankster. But after tracking the hacker for almost a year, Stoll discovered an international spy ring, operating out of West Germany, which sold the data it collected to the Soviets. This is the subject of his book "The Cuckoo's Egg".