German security researcher  Stack Smashing spent a few hours and destroyed firewalls of a few AirTags to find out that the microcontroller could be reflashed. It is possible to alter the programming of the microcontroller, to change its functionality. A hidden debug mode was also found that gave developers access to extra info about its hardware. The AirTag is an Apple accessory that enables to locate of items to which it is attached using the Apple Find My app.