Guessing: even if you don't have assets in EU, you have a Google (or Facebook, or Amazon) account, and Google has assets in EU. EU could ask Google to ban you, or else.
That seems like a bit of a stretch, unless you were actively using Google's services as a tool of your wrongdoing. The EU would be forcing an unrelated private company to act as an arm of law enforcement. It would be like the local police punishing you for speeding by leaning on Applebee's to refuse you service.
Maybe there's a legal precedent for that sort of thing, but I'm not aware of it.
Maybe there's a legal precedent for that sort of thing, but I'm not aware of it.