According to news sources, Welles' performance of War Of The Worlds had "upwards of a million people, convinced, if only briefly, that the United States was being laid waste by alien invaders." Quite the prank, except that Welles was as shocked as everyone else. His show, The Mercury Theatre On The Air, had been around for months, adapting famous literary works as radio plays every week without anyone ever thinking they were real. When they premiered the show with Dracula, it didn't cause people to loot their local garlic-and-stakes emporiums, so what was so special about War Of The Worlds?
If anyone was to blame for tricking people into panicking, it was the newspapers. During the '30s, print media was in decline (can't imagine what that's like), with people preferring to get their news from their newfangled talkin' machines. So when they heard of Welles acting out a newsreader announcing the end of the world, they saw a chance to smear the radio as spreading fake news, proving that people should only trust print journalists -- which we now know is even dumber than believing aliens are invading.
However, the embarrassing truth for Welles was that not enough Americans even listened to his show for it to cause pandemonium. As the alleged mass panic was kicking off, a radio ratings service was telephoning households to ask what they were listening to. Only 2 percent answered that they were listening to "the Orson Welles Program," and none said they couldn't talk because they were helping Pa load his shotgun to stop the aliens from probing Ma. The only thing the "scandal" wound up doing was make the 23-year-old Welles famous throughout the country as the world's most convincing storyteller, which must've really helped his burgeoning film career. So what we're trying to say is this: Thanks for Citizen Kane, fake news.