Oh, I know. But libel does clearly extend to cyberspace, which was the main point of the question, I think ;)
Many folks miss this key point to win a libel suit: You must show/prove how you were damaged by the statement in question.
If I say libelous statement about somebody and it's proved to be untrue, that's fine, but now how do we award damages? Proving damages is tough - its a grey area, but it's required to win a successful libel suit.