Grant Raphael wanted revenge after a row with his old school friend and former business partner Mathew Firsht, says an article in the Guardian newspaper. So he disseminated a web of lies via Facebook, which remained on the site for 16 days. In the first case of its kind in the UK, where libel prosecutions are largely the province of celebs, Frisht took Raphael to court and won £22,000 (€27,908).
See full story here http://www.guardian.co.uk/uk/2008/jul/25/law.facebook but the message is, you can't act with impunity on social networking sites - no matter how mad you are.