Bluetooth exploit can track and identify iOS, Microsoft mobile device users - ZDNet

https://www.zdnet.com/article/bluetooth-vulnerability-can-be-exploited-to-track-and-id-iphone-smartwatch-microsoft-tablet-users/

A flaw in the Bluetooth communication protocol may expose modern device users to tracking and could leak their ID

can be used to spy on users despite native OS protections that are in place