Thus, it was probably inevitable we'd see the two happenstances collide. Recently, the sports world helped make it happen. Tony La Russa, the revolutionary manager of the St. Louis Cardinals, is suing Twitter because some low-life started a Tony La Russa Twitter page. His grounds are on trademark infringement and "dilution, cybersquatting, and misappropriation of name and likeness."
This is not the first lawsuit involving Twitter -- you can always count on Courtney Love, right? -- but it is the first one (at least that I could find) in which a public figure is suing due to someone else pretending to be him/her. Twitter removed the fake La Russa page just hours after the lawsuit was filed, so we can't see what was being posted there, but the lawsuit alleges that there were Cardinals-related updates sometimes containing vulgarity.
As for La Russa, it's easy to say something like "lighten up," but would you really want someone pretending to be you and posting things you have never or would never say? I am firmly in his corner on this one -- if for no other reason than to punish people for having no lives and creating fake pages.
Some individual public figures can stake a legitimate claim that better monitoring than simple "terms of service" needs to be done at the creation stage to ensure accuracy and protect against their individual freedoms being violated before the fake pages are removed.
Maybe La Russa is the man to get the ball rolling. After all, he is the guy who changed the face of baseball by batting his pitcher eighth. [I feel compelled to add that this was sarcasm and far too many people didn't pick up on it. Sigh.]