What do all the following stories have in common?

Lawrence Cusack, a New York lawyer, comes up with a treasure trove of handwritten Kennedy documents, including one suggesting that the late president paid hush money to actress Marilyn Monroe to keep secret an affair and a Mafia connection. That crack investigative reporter, Seymour Hersh, accepts the documents as authentic until they are proven to be forgeries.

Next, Federal District Court Judge James Ware has for more than 30 years presented himself as the older brother of a black youth gunned down in 1963 by white racists in Birmingham, Ala. Ware is exposed as having latched onto a story involving another person - also named James Ware - and Judge Ware did not lose a brother at all.

Next, the case of Tawana Brawley - a black woman in New York who 10 years ago claimed abduction and rape by white law enforcement officers, a charge a jury found to be invented.

Next, there circulates on the Internet a speech that novelist Kurt Vonnegut supposedly gave at the MIT graduation last June. It is a humorous speech, full of pithy counsel like "Enjoy your body" and "Wear sunscreen." Vonnegut is widely quoted on the speech before it is disclosed that it was not a Vonnegut speech at all, but a column in the Chicago Tribune by Mary Schmich.

All of the above are hoaxes - an increasingly prevalent phenomenon in this age of virtual, if not virtuous, reality. The dictionary defines hoax as "a humorous or mischievous deception." Clearly, the matter is more complicated than that.

In the case of the fake Kennedy papers, money must have played a part. In the case of Judge Ware, some need to enhance his identity seems to have been the motivation. The Vonnegut speech was probably a practical joke.

I thought back to some other famous hoaxes - Washington Post reporter Janet Cook, who invented an eight-year-old heroin addict named Jimmy and won a Pulitzer Prize.... Mark Hoffman, who sold the fake last writings of Mormon church founder Joseph Smith.... Clifford Irving, who forged an autobiography of Howard Hughes.... the unknown person who forged the diary of Jack the Ripper.... and the fake Hitler diaries.... the fake photo of the Loch Ness monster.... and, back to 1912, the pile of bones in Sussex, England, presented as the prehistoric Piltdown Man.

The oldest hoax I can remember was a half-century ago, when I was reporting from the Netherlands. Han van Meegeren forged Vermeer paintings. So well, in fact, that the police did not believe they were forgeries until he painted a new "Vermeer" in his jail cell.

And then, of course, Anastasia, the "lost Czarina" ... the several women who claimed to be the surviving daughter of the Czar killed by the Bolsheviks. Some of them apparently believed they were Anastasia. Such is the power of delusion.

I remain fascinated by the phenomenon of hoaxes ... for fun, for profit, and because we have come to live so close to the border of fantasy.

* Daniel Schorr is senior news analyst for National Public Radio.