[ryandrake]

The below applies to the USA:

Aircraft are (in general) required to transmit ADS-B information in the clear over RF that contains information identifying the aircraft.

Aircraft registrations are public. You can go to the FAA[1] and look up who owns what airplane and what their address is. Some aircraft owners choose to obfuscate their ownership through shell companies or LLCs.

Passenger manifests are collected by the FAA for airlines and charter flights, but they are not made available to the public.

So you can know who owns the plane that's flying over your antenna, but not who's on it.

1: https://www.faa.gov/licenses_certificates/aircraft_certifica...