There's also thousands of child porn sites, millions of people downloading pirated content etc.
The law on the internet is a fickle thing.
I'm fairly sure that in just about every thread on here regarding an individual/organisation etc I can find a post that could arguably be construed as libel. I'm not saying that people shouldn't be responsible with what they post, and that the moderators shouldn't, well, moderate...but if you jump behind the libel shield half of the threads on this site go missing.
It would become the Professional Pilots Network. No space for rumours