It doesn't have to come to EU to get this data though, all it has to do is start federating. I'm really curious how is that all going to work out, legally speaking.
Not totally true, the real value is combining data from different sources, but since the data they get wont have your email /ip/device/contacts etc it will be a lot harder to harvest usefully for advertising. Maybe they will figure out things to use it, but what they can use is already quite public, so they don't really need to federatie for that