This NOVA special is based on Clifford Stoll’s novel, “The Cuckoo's Egg: Tracking a Spy Through the Maze of Computer Espionage.” Clifford’s search for a 75 cent accounting error led to the discovery of a computer cracker who broke into a computer at the Lawrence Berkeley National Laboratory, exploiting a vulnerability in the movemail function of the original GNU Emacs.
Clifford would later acquire the investigative assistance of agents at the FBI, CIA, NSA, and Air Force OSI. Since this was believed to be the first documented case of cracking (Stoll keep a daily log book of the cracker's activity) there was some confusion as to jurisdiction and a general reluctance to share information (Stoll quotes an NSA agent as saying, "We listen, we don't talk").