I agree with that, however, since these sites/services cannot be held responsible by law for the actions of their users - though I believe that has been reevaluated in some places - and they even seem to make profit off of it, it won't happen unless there's external pressure. And starting with the German ban on hate speech, there's now a precedent to go forth, though this will take a lot of time since various countries have various stances on the matter.The world would be a much better place if Twitter, Facebook and other social media moderated its content like neogaf does.
And in some places, they'd prefer to fuck over the internet entirely. *cough*EU*cough*