It's all about what we call a "reasonable expectation of privacy" right? And all Sweeney did was publish information that was already publicly available[1], right?

[1] https://en.m.wikipedia.org/wiki/Jack_Sweeney

So if someone goes around taking a picture of your vehicle everywhere you go you won't have any objections to that because you have no reasonable expectation of privacy and it's all publicly available information. Got it. I'm sure you'll stoically accept such behavior rather than scream for it to stop.

This is exactly what highway toll systems and ALPR enforcement already do.

But even on the public side: yes, this would be entirely appropriate. It's not clear what the alternative would even be; what would it look like to have civilian evidence in e.g. traffic accidents if people weren't allowed to take pictures of others' cars?

1. Highway toll systems aren't random people on Twitter.

2. In such a case you have a need to know that supersedes one's right of privacy. Are you saying you have a need to know where Elon Musk is at all times?

Elon Musk is the antithesis of a "random person on Twitter." He's the CEO, and one of the richest men on Earth to boot.

I don't have any particular need (or interest) in knowing where Elon Musk is. I also don't know where he is at all times with the information in this flight tracker: I only know the parts that are already necessarily public.

Law is fundamentally casuistical in nature: there are standards that apply to John Q. Publics (like you and me), and there are other standards that apply to the Barbara Streisands (and Elon Musks) of the world.

Ok, so then can someone do this to you personally?

Because you posted a bunch of info public on your account.

Seems like someone could easily track down a bunch of info on literally you personally.

Tail numbers and flight paths is publicly available information.

https://registry.faa.gov/aircraftinquiry

https://www.faa.gov/air_traffic/flight_info

So is your license plate number, and you have no reasonable expectation of the privacy of that information... but you wouldn't be happy if someone went around tracking everywhere you went now would you?

How are those two things related at all?

1090 MHz

Relitigating this is not going to be fruitful: Elon Musk is a public figure who chooses to fly by private jet. Callsigns and flight status are public information by necessity.

Being a public figure does not mean you have a right to stalk and harass him. It means you get to have a higher bar to charges of defamation for things said about them and nothing more.

Tracking an aircraft's callsign does not remotely approach the bar for "stalking and harassing."

Put another way: the courts have overwhelmingly recognized the rights of "paparazzi": if you're a public figure, there is going to be independent public interest in your life.

The interest can't be intrusive (meaning that it doesn't enable someone to break into your house and take pictures of your underwear drawer), but it does allow citizens to use any public information available to them. Since airplane information is public by necessity, there is no reasonable legal structure that enhances Musk's privacy without compromising well-trodden expression rights.

Just so we're clear: I'm not free speech absolutist.