Please read about FATCA

That isn’t about data protection— it’s actually the opposite, it’s about Euro banks sharing data with US authorities. Furthermore the unintended consequence of FATCA is that many Euro banks stopped allowing accounts from Americans because they didn’t want compliance risk. GDPR is having the same effect: US companies will refuse service to Europeans because of compliance risk.

How many European companies deal with US health data (HIPAA)?

I am a US citizen who, until last week lived in France. I wasn’t protected by HIPAA in Europe. Interestingly, HIPAA is stronger than the protections provided by U.K. law. For example, practitioners in the U.K. actually use Skype for mental health consultations — which would be a huge HIPAA violation in the US.

If it worked the same as GDPR, I could start forcing them all to just by emailing them my health records.