When talk turns to radio hoaxes, generally the conversation begins with Orson Welles and the Mercury Players 1938 on-air dramitization of H.G. Wells' novel "The War of the Worlds." Americans running screaming into the streets, reportedly, at the idea that Martians were invading, got lots of Congressmen mad at the time, David Oxenford reports at the Broadcast Law Blog, but didn't change anything. "Essentially, through some well-publicized apologies by Welles and others involved in the program, and a promise by the network to take steps to prevent it from happening again, the FCC closed its investigation and no law was passed by Congress," Oxenford wrote. Fifty years later, in the early 1990s, several on-air April Fool's Day incidents did cause the Federal Communications Commission to update their rules, Oxenford reports. Announcers at a one station claimed someone had taken them hostage, and another station pretended that a local trash dump had exploded like a volcano, sending burning trash airborne. Both times, first responders were called to non-existent emergencies, risking lives. So the FCC adopted Section 73.1217 of the Commission’s Rules, preventing stations from discussing a "crime or catastrophe" on the air, if the broadcaster (1) knows the information to be false, (2) it is reasonably foreseeable that the broadcast of the material will cause substantial public harm and (3) public harm is in fact caused. The FCC defines public harm as "direct and actual damage to property or to the health or safety of the general public, or diversion of law enforcement or other public health and safety authorities from their duties."