War of the Worlds
Orson Welles' radio adaptation of the classic H.G. Wells novel The War of the Worlds is regularly cited as the best hoax of all time. And for good reason: performed by Welles' Mercury Theatre on the Air as a Halloween special on Oct. 30, 1938 (and aired over the Columbia Broadcasting System radio network), the radio play — which took the form of a series of faux newscasts — caused many listeners to believe that an actual alien invasion was taking place. As a result of the broadcast, it has been variously alleged that residents fled the area, some smelling the poison gas or even seeing flashes of the fighting in the distance. It's even been reported that people went to the "scene" of the events in New Jersey to see if they could catch a glimpse of the action, including some astronomers from Princeton (who should have known better) looking for the "meteorite" that had fallen. According to Richard J. Hand, author of Terror on the Air!: Horror Radio in America, 1931-1952 historians "calculate that some six million heard the CBS broadcast; 1.7 million believed it to be true, and 1.2 million were 'genuinely frightened.' "