I believe that in a society that has free speech, there is a duty of the member's of society to exercise their free speech and disassociate from those acting unethically. Particularly for unethical actions that cannot be prosecuted due to the rights afforded to all.

Now while there are a lot of things that facebook probably can be prosecuted for, there are many things that they probably can't be. So I think we have an obligation to shame and shun those who act in reprehensible ways. And obviously in proportion to how culpable/complicit those individuals are.