Clifford Stoll is an astrophysicist who wrote The Cuckoo's Egg: Tracking a Spy Through the Maze of Computer Espionage, a non-fiction work about Stoll's discovery of a hacker accessing sensitive U.S. government networks and then selling the information to the KGB. Stoll has also written Silicon Snake Oil: Second Thoughts on the Information Highway, a book analyzing the present Internet usage.