They seem like the ultimate authorities, but to prevent plagiarism from the competition, some dictionaries insert fake entries. If two contain the same made-up word, the originator can accuse the other of copyright infringement. The practice is also common in encyclopedias. The traps are called “Mountweazels,” named for a phony entry in the 1975 New Columbia Encyclopedia. (Lillian Virginia Mountweazel was a fictitious person who photographed rural mailboxes. She died in an explosion while on assignment for the also-fake Combustibles Magazine.) But the practice doesn’t hold for all reference books. In the 1980s, Fred L. Worth, author of The Trivia Encyclopedia, added a fictitious entry about the TV detective Columbo (stating that his first name was Philip). When the fact appeared in Trivial Pursuit, Worth filed a $300 million lawsuit. The game’s attorney argued that facts aren’t copyrightable, and the case was tossed out.