Facebook is warning it may pull out of Europe over a decision by Ireland’s Data Protection Commission (DPC).

The DPC issued a preliminary order to stop Facebook from transferring the data of European citizens to servers in the US. The EU has become increasingly wary of its citizens’ data being held in the US, given the US government’s penchant for digital surveillance.

According to Vice, however, Facebook has warned that the DPC’s decision may cause it to pull out of the EU altogether. This would leave some 410 million users without access to Facebook and Instagram.

Yvonne Cunnane, Facebook Ireland’s Head of Data Protection and Privacy, said “it is not clear to [Facebook] how, in those circumstances, it could continue to provide the Facebook and Instagram services in the EU.”

What is even more unclear is if Facebook is serious about its threat, or if this is a game of legal chicken. It seems unlikely Facebook would be willing to abandon an entire continent worth of users, opening the door for a home-grown competitor to take its place.