@c0debabe @jonw@hackers.town is it even opt-in? The way I'm reading Apple's sparse marketing, and other articles it uses all Apple devices; also looking at https://www.cnbc.com/2021/04/27/apple-airtags-versus-tile-tracker-how-they-compare.html "Tile has sold more than 35 million devices" vs "Apple’s AirTag is similar, except it taps into not only other AirTags but also Apple’s existing network of iPhones and Macs, which is nearing a billion devices."
@f0x @c0debabe If I could venture a guess, I’d say it probably uses any device that has “find my” turned on, which based on the guided path of setup is going to be a vast majority of apple devices.
(Incidentally, this is why “opt-in” isn’t real if the encouraged option is “on.”)