They can freeze their assets. They can basically do everything you can do against a company that doesn't obey the law.
Facebook Norway AS did, however, only have a revenue of about 6.6 million USD in 2022, with a profit of 3.6 million USD, according to https://www.proff.no/selskap/facebook-norway-as/oslo/reklame... . They have 27 employees. The revenue from Norway are however much bigger and was speculated to be 233 million USD in 2021: https://e24.no/naeringsliv/i/A3r1Mz/facebook-bokfoerte-bare-...
And seizing those DC's is childs play for a nation state, where are they going to take them?