Facebook already has data centers in the EU so it could "easily" bring up facebook.eu for its eu users, subject to EU laws, and not ship data to the US. They'd

Facebook already has data centers in the EU so it could "easily" bring up facebook.eu for its eu users, subject to EU laws, and not ship data to the US. They'd also have to spend some money on lawyers to ensure that facebook.eu is not subject to US legal action, but that's not particularly difficult. This would slightly inconvenience the small number of people who have facebook friends in both the EU and the US (they'd have to have two facebook windows open) but that's not facebook's problem.