Britain has reported twenty incidents this year in which hoaxers broadcast phony air traffic control messages to airliners. None of the messages caused crashes, but many have caused various problems including near-misses and mis-routed flights. The first known hoax was in the US in 1995; that hoaxer is now serving a ten-year prison sentence. While Britain has the most current hoaxes (at least three individuals are thought to be involved), other countries have reported sporadic hoaxes including several such broadcasts in the US.--Stephen V Cole