“People like to lie,” he said. “They get a thrill from it. There is a little hit of dopamine when you lie, especially a lie that is believed by somebody else.”

Many of the fake deaths, including Mr. Danza’s, were generated on Fake a Wish, a Web site that promotes a “celebrity fake news hoax generator” that allows anyone to create a baseless story attributed to Global Associated News.

The pranks aren’t victimless. Mr. Springer was told that he died while driving a friend’s vehicle on a highway. He immediately checked in with his family. “My wife couldn’t read it,” he said. “It was just too difficult for her.”

Celebrity death hoaxes are not new. Mr. Bell pointed to the rumors surrounding Mark Twain in 1897, to which he famously responded, “The report of my death was an exaggeration.” What’s different today, he said, is the ease and speed with which such rumors can be created and circulated.

Often, all it takes is a Twitter hashtag or Facebook page to set a hoax in motion, as has happened to Bill Cosby, Jon Bon Jovi and Justin Bieber, who over the years has been shot in nightclubs, died in car crashes and overdosed on drugs.