There used to be lots of European posters, not so much now - to name a few off the top of my head:
Killer B, Ronnie Roots, Stevie Cage, Birgundy (when he lived there), GlennK had a stint in London I think. Many others
And I'm not sure it matters how many, the issue as I understand it (and I could certainly be wrong) is that you either comply or lock your website out of reach of anyone in the EU (or face penalties), a process that I would think would be pretty expensive though my knowledge of tech is not much.
As for the fact that WS is a US company, these days extra-territorial over-reach is pretty common. No points for guessing which country probably leads the world in that regard!