Facebook's business model seems to me the most fragile one. They rely a lot on automated moderation and are seriously understaffed in the "human moderator" segment.
It is likely that various countries will push Facebook around and force it to somehow respect local laws regarding freedom of speech or criminalization of hate speech. This needs a lot of human moderators whose aggregated compensation might sink the company, unless it starts charging the users.
But charging the users turns them into customers and makes them way more assertive against their business partners in disputes. Yet another source of extra costs.
It is likely that various countries will push Facebook around and force it to somehow respect local laws regarding freedom of speech or criminalization of hate speech. This needs a lot of human moderators whose aggregated compensation might sink the company, unless it starts charging the users.
But charging the users turns them into customers and makes them way more assertive against their business partners in disputes. Yet another source of extra costs.