My friend is a contractor who sometimes maneuvers his clients a little. He recently took $10,000 from a client but did not perform all the work that they wanted. He covered himself by wording the contract ambiguously. Now the client filed complaints with the liscensing board, and set up a website broadcasting to the whole world details about the incident and about what an untrustworthy contractor my friend is, and advising people not to hire him! This could really damage my friends business. Can my friend sue the client, or is this a free speech issue with the client just relating his own opinions?