Not disagreeing with you, but "criminals" is not a Boolean variable when you have power over those who determine who is and isn't a criminal.

Facebook (and other big social media) has a lot of power over those who define and enforce the laws, both within the bounds of the existing laws, and within a grey area where they'd be technically breaking the law, but nobody would want to enforce said law on them due to potential repercussions (Facebook could instantly shut down a lot of politicians' careers by just airing their dirty laundry, on which Facebook has a lot of visibility due to its omnipresence).

Those who make the laws rely on Facebook to succeed in their own personal interests (getting elected, which means money & power).

The problem here isn't just Facebook, it's the people that are supposed to be drafting & enforcing laws in the best interests of society are instead doing so to pursue their own personal interests instead. Facebook is just coming along for a free ride - can't really blame them.