The Trouble with "Twibel"

In coverage of the first libel settlement award in Britain stemming from a posting on Twitter, a number of articles state that in the United States, libel via Twitter is referred to as "twibel." 

This is stated matter of factly in stories by Agence France-Presse (AFP), the Daily Mail, and The (London) Times (subscription  required), which used the term in a headline. PC World 
and ComputerWorld UK both use the term without attribution.

But it's unclear where the term or the "fact" that it's an American term came from; I've never heard the term "twibel" used to refer to libel via Twitter.  This isn't too much of a surprise, since there hasn't yet been a defamation trial stemming from Twitter in the United States: the two cases that were the leading contenders both ended prior to trial.

A Google search for the term turns up a woman who's is tweeting the Bible; a disparaging term for the Twilight teenage vampire series; and a British discount code website; but no other Twitter defamation cases.

But it's a cute term, and one that's likely to propagate -- once there's actually a case in the U.S. to apply it to.