The Pequod Review:
Clifford Stoll's The Cuckoo's Egg is the thrilling true story of how Stoll (a computer scientist at the Lawrence Berkeley National Laboratory in the 1980s) noticed a 75-cent discrepancy in an internal accounting system and eventually traced it to the intrusion of a KGB hacker (Markus Hess) operating out of East Germany. The cat-and-mouse chase between Stoll and Hess becomes as gripping as a spy novel, while also providing useful descriptions of coding and the structure of computer networks. And Stoll has a Feynman-like curiosity as he devises unique methods to track Hess — e.g., a pager alarm that would notify Stoll whenever Hess was operating in the network, or the tracking of Hess's keystrokes to determine his location. The book was made into a very good NOVA documentary ("The KGB, the Computer and Me").