Not exactly?
It's certainly not criminal law. Proof beyond reasonable doubt has no place here.
But it's also not exactly the relationship between a host and guest, where the guest has no rights save what the host grants. Website terms of service purport to be contracts, so there is a contractual rather than ex gratia basis for the relationship.
So, begin interpreting website terms of service as contracts of adhesion, and read in a duty for website operators to enforce those terms fairly, with a reasonable basis (on the balance of probabilities) for harmful decisions.
This isn't the current law, of course, but it's not hard to imagine the law reaching that place from here.