Of course. It is posting in a way that may earn you a visit from federal authorities who are there about language you are using or threats you are making in a public forum.
When I say “send him to The Hague,” I mean send him to be tried at the International Criminal Court. It’s a global court, not a European one. It holds trials under international authority and saying someone should be sent there isn’t a desire to make them the Dutch government’s problem.