Or take the bizarre but instructive example of the woman who claimed to have had an implant to add a third breast — clearly an example of an implausible story that was too good to check. Initial reports circulated widely on social networks, totaling over 188,000 shares according to Emergent’s data. The story was quickly discredited after it was reported that a three-breast prosthesis had been previously found in the woman’s luggage, but the articles reporting that it was false never attracted even one-third as many shares as the initial false reports.

That hoax may seem silly, but it’s instructive about the problem with rumors — they’re often much more interesting than the truth. The challenge for fact-checkers, it seems, is to make the facts as fun to share as the myths they seek to replace.