Facebook doesn’t have the ability to prosecute people for War Crimes. They can (and routinely) share information with law enforcement for things that they deem abhorrent (human trafficking, notably of children).

What they can do —like in this case— is to sue in civil court. What they can also do is to kick the people that they are suing away from their platform for violating their terms. It’s actually not rare (several people involved with Cambridge Analytica were locked out of their account) so “aggressive” is a stretch, but that kind of side-show is representative of the internal tone of the discussion.

A friend talked about “their large legal team” and, yes, that’s more to the point. Said legal team has a lot of friends familiar with Den Hague so I wouldn’t be surprised if your wishes become reality.