This doesn't excuse facebook, however. This isn't just their ad business I'm speaking of - I was merely pointing out that suggestive paintings are too much. Pointing out they punish artists that paint tasteful nudes. Historical photos are a grey area, and it has taken heads of states speaking out for those to be reinstated.
These are merely normal people's posts.
Yet allowing posts that harm others and entire groups that do the same? Yup, allowed. Because they choose to allow such posts, they share responsibility. They choose to turn a blind eye to anti-vax groups and the like.