They would need to a have an independent legal entity in the EU on top of hosting data in the EU, perhaps only owning shares in that entity. The construct would

They would need to a have an independent legal entity in the EU on top of hosting data in the EU, perhaps only owning shares in that entity. The construct would need to be setup in a way that three letter agencies in the US (and courts) would have no way of forcing the US company to hand over data - not sure this is possible IANAL.