FORTUNE -- Last week, a Swedish design firm called Day 4 mocked-up a 3-D rendering of an odd-looking screw and posted it on Reddit, hinting that it was Apple's (aapl) latest attempt to keep users from messing with the innards of its devices.
In a matter of hours, news of the "asymmetric screw" had spread across the Web, generating hundreds of credulous headlines, angry tweets, Google+ commentary and YouTube videos.
On Monday, in a post entitled How we screwed (almost) the whole Apple community, Day 4's Lukasz Lindell announced that the screw was a hoax -- a "test" to see how easy it would be to spread disinformation through the media.
He needn't have bothered; we already knew. The history of the press is littered with hoaxes that were cleverer and more widespread than this one.
- In the wake of the Watergate scandal, career prankster Alan Abel hired an actor to pose as Deep Throat at a New York press conference that drew 150 reporters and an offer of $100,000 for the rights to the story. The news conference ended when "Deep Throat" quarreled with his wife, fainted and was carried away in an ambulance.
- After O.J. Simpson's acquittal, Joey Skaggs -- whom the New York Times called "the Willie Sutton of the counterfeit news release" -- got several major newspapers and legal journals to write stories about Solomon, a computer program that would take the uncertainty out of jury trials. CNN sent a camera crew to interview the program's creator in a SoHo loft filled with actors posing as refugees from Microsoft (msft). CNN, which like Fortune is owned by Time Warner (twx), broadcast the segment with an intro that declared: "There are those who think that the Sixth Amendment ought to be amended to include trial by mainframe."
- In 1986, 30 million viewers tuned in to a heavily promoted live television special in which Geraldo Rivera broke open a basement room in Chicago's Lexington Hotel that he had been told was a vault owned by Al Capone. Instead of ill-gotten gains (or dead bodies), the vault was filled with dust and debris. Rivera's reputation as a serious journalist never quite recovered.
But anybody can be fooled if the evidence is sufficiently convincing. After all, it took paleontologists 40 years to prove that their beloved Piltdown Man was forgery.