I can go on one of those websites, see all those flights, but I have no idea who they belong to or who's on board.
That changes once someone specifically links a private jet to someone.
Within the EU I'd be interested in the ramifications with regards to the GDPR.
the linking is done simply by looking up who the plane is registered to, and that is also public information.
you can of course always go the other way, look who owns a plane, and the go to flight information from there.
there is nothing private about any of the information used in the process.
I would ponder the GDPR's definition of personal data before making such definitive claim.
https://dataprivacymanager.net/who-does-the-eu-gdpr-apply-to...
That's not true.
No.