If we're speaking about privacy, then ADS-B is just one element of concern. The FAA is now finalizing new Remote ID regulations that will require all unmanned aircraft over 0.55 pounds to be identified and tracked in real time, with data shared back to authorized data aggregators. This is a major concern to hobbyists (think first person quad-copter racing), because the details of the proposed rules make it virtually impossible for hobbyists to fly amateur built aircraft, while giving cart blanch to commercial drone operators (ie delivery services) to fly anywhere assuming they have the resources to comply with the new Remote ID rules. The FAA is essentially saying they have the authority to regulate all navigable airspace, and since UAVs can fly inches from the ground, they are claiming authority to regulate who flies an inch above your own property. The rules are open for comment right now https://www.faa.gov/uas/research_development/remote_id/. A good summary is to read DJI's point of view. https://content.dji.com/we-strongly-support-drone-remote-id-...
I'm not sure where everyone else comes down on these navigational tracking techniques? Here's my view.
There are times when I do want to let everyone know where I am and who I am. This allows others to avoid running their vehicle into mine and improve rescue efforts if I'm in danger. So I think these sorts of digital beacons and aggregators can be a great improvement to support that mission.
If the nav beacon is mandated for safety reasons, I do not think that I should be required to give my personal information if I choose not to, and if there is a navigational concern, I don't think I should give more information than I need to to enable safe navigation. I think it's enough to provide telemetry (e.g. there is a boat, plane, car or drone at location x, y, and z).
I personally believe that people should own their data and forcing people to give more information than required to accomplish the task (e.g. navigation) is a problem for me. DJI's position is closer to what I'd prefer to see in this case.
