Aggregation of this type of public data (face recognition, license plates, cookies, etc) can absolutely create new privacy concerns. We should have privacy laws that protect us from this type of aggregation. Whether those laws should extend to plane transponder data comes down to the tradeoff between loss of privacy/security and transparency gains.
What I don't like is the argument that purely because some piece of information is "public", we should allow companies to aggregate and sell this data.
100% when it comes to getting legislation out that that limits what data companies can aggregate and sell. But I dont think the current location of the jets of the rich.... that's the starting point for the conversation?!
And as a reminder, these planes literally broadcast their location themselves to the public.
I do think it is worth pushing back on the argument that just because data is public or broadcast, that makes aggregation of that data automatically OK. (edit: e.g. many Bluetooth devices are set to be discoverable and so broadcast a unique Id that could easily be tracked an aggregated to reveal a LOT of location data)
I do think there are some strong arguments for allowing the aggregation of flight transponder data. I'd like to people making those arguments (such as the value of transparency in fighting corruption) rather than backing dangerous lines of argument because they don't like Musk or rich people in general.
Edit 2: One of the things that makes what ADSBExchange doing seem OK to me is the fact that in addition to selling the aggregated data commercially, ADSBExchange makes the data publicly available for non-commercial use. To me, that really helps tip the scales as it supports the transparency argument
What I don't like is the argument that purely because some piece of information is "public", we should allow companies to aggregate and sell this data.