The information from ADS-B transmitters is public only by design accident (there's no good way to do it otherwise), not because it has to be public. Nowhere it'

The information from ADS-B transmitters is public only by design accident (there's no good way to do it otherwise), not because it has to be public. Nowhere it's mandated that the information it shares should be public. And before the internet, it was not public at all!