Plus, they need the cooperation of governments. Their patents are just pieces of paper without governments enforcing them, for example, and their data centers need special power solutions. Governments don't trust companies that ignore government regulation.

And, even if they hope that the US government is more lax with their restrictions and will turn a blind eye, the US is very heavily dependent on the OECD working, and not helping the EU prosecute blatant criminals would be a big problem for American credibility.

This is not even getting into the fact that the EU is a much larger market than the American market is, too.

In practice, just pretending regulations doesn't exist (depending on the regulations in question, of course) can be stupidly expensive for the company in question. Share holders don't like stuff that's risky and expensive and would replace a CEO that mad.