Any of these things would have put an actual stop to @elonjet, and the PIA solution would have prevented harassers from simply picking up with FlightRadar or any other tracking service.
The fact that he didn't do anything to increase his own security except for banning one of his company's users tells me this is not about personal security, but about exerting control over his company. That's his prerogative, but it's bizarre that he chooses to put up a facade instead of just adding "don't be an asshole to Elon" to the terms of service, which appears to be the actual endgame here.
You can buy the antennas for like $100 and share the data in real time with whoever you want.
This is amusing because the ElonJet guy was actually a fanboy (originally, probably not anymore as he's being sued by Elon).