Microsoft have to choose whether to operate in the EU. There's been a long struggle between conflicting rules of US unaccountable intelligence access vs. EU privacy law ("safe harbour") that is relevant here. https://blogs.microsoft.com/on-the-issues/2015/10/06/a-messa...
Honestly, the day may come when some US corporations decide operating in the EU is more trouble than it's worth. I don't really expect that--it's a big market--but it could happen.
Naturally — one cannot be a servant of two masters, and some US legislation does at least seem to be incompatible with EU legislation: https://en.wikipedia.org/wiki/Max_Schrems
Same is of course true for Chinese companies deciding to not bother operating in the USA, or UK companies deciding it's not worth the effort to operate in Argentina.
But it's not likely to be a big deal if it does, because software … how can I put this?
The saying goes "the first 90% takes half the time, the second 90% takes another half of the time, the third 90% puts you over-budget", etc. but that same effect also means it's easy to catch up most of the value even with something relatively mediocre.
The combined armies of every member state of the EU, if it came to that.
Well before that point, they can just go through a normal court process because the EU has been empowered by the governments of each member state to write such legislation.
