IANAL and this obviously won’t happen (because it’s one of if not the stupidest way to go about it right from the get go) but still:

They can literally demand any and all European ISPs block all their traffic, they can still raise the fees and if they don’t pay accrue interest/late claims on it. Will this change anything? Not immediately, but the moment that company does anything the courts can reach they are in a whole lot of trouble.

Anyway besides this are there really companies that are so US centric that a European court can’t (like really absolutely can’t) reach them?