Funnily enough, quite recently, I read that Facebook were introducing a new rule that held posters responsible for the replies they received. Not much chance of anybody abusing that rule, lol.
It's doubly amusing because when Zuckerberg was in front of a Senate Committee last year, to explain why IS and various hate groups were allowed on Facebook, he said 'We're not responsible for content, we are not a publisher, we are just a platform'
Lol, talk about having your cake and eating it.