There is a case in the Philippines where a facebook user called for a boycott of a celebrity doctor. The doctor is sueing the user for Internet-based libel in a country where there are no laws governing libel on the Internet. Indeed, most of the Internet is fairly anarchic in that regard–which is why search engine reputation management exists.
http://www.businessweek.com/globalbiz/content/sep2009/gb20090925_532132.htm