

there were thin (~2mm) sticker-type Bluetooth tags […] No battery, just a passive coil that could be found with Bluetooth signal and an app that shows how close it is.
Sounds kind of like UHF RFID, which are common in places like warehouses and can be done at a distance, but even higher frequency?
I imagine range was a huge issue. Unless you have an extremely powerful bluetooth tranceiver and a very high gain antenna (i.e. not a phone, a professional radio system), the inverse square law will mean you won’t have enough energy to activate the electronics in the tag after a fairly short distance. Would probably work for finding something in your house though.



























It may not be harmful by itself, but combined with other information it can definitely help identify you to your account. It could easily be the final piece of information that enabled you to be doxxed.
Loss of privacy is cumulative, like radiation.