Why would anyone confront Facebook with something like that?
Facebook is happy that we, the users, share anything at all on our walls for others to read.
This is how Facebook makes its living. They sell add space on top on whatever we choose to share on our walls. From a mercantile point of view Facebook shouldn’t really care whether what is shared by its users is legit or not, they simply must enforce the rules – no pornography, no open incitement to hate, no bullying, etc., etc…
We do the sharing, we bear the responsibility for our acts.
And it is we who will, eventually, experience the full consequences.