I just ran into a really good video about online defamation, what to do about it, how to react and legal recourse. It is 5 parts, but extremely worth watching.
In this video he brings up some very interest points. One that I thought particularly interesting is the argument that websites are not liable for what is on there website. They are all hiding behind the communications decency act which was originally too broad to begin with but that the
courts are trying to define rules and regulations around it so that websites be held liable in certain instances.