Like any other regulation? Rules, Letters to enforce those rules, Strongly worded letters to enforce those rules. Announced and unannounced audits to ensure c

Like any other regulation? Rules, Letters to enforce those rules, Strongly worded letters to enforce those rules. Announced and unannounced audits to ensure compliance. In the extreme case and only if needed, fines, warrants and searches or revocation of access to customers (EU companies wanting to advertise) and resources (FB users in Europe). FB knows that and they also know this particular case is very public so they will either comply (probably hesitantly and last minute) or withdraw from the EU market if the bean counters say it's not worth the effort.