I too hate videos and didn't watxh this one yet, but the slides seemed clear even without the talk:

    - Tazer/Axon makes some kind of police oriented hw/sw platform thats deployed on police bodies and cars
    - which uses BLE
    - Tazer/Axon has their own BLE MAC address prefix, which is published by the FCC 
    - The less significant bytes of BLE MAC address are a unique id for the hardware, which usually maps 1:1 with 1 officer or 1 car
    - So by listening to or probing some BLE crap you can infer cops are present close to where that MAC address prefix is, and by recording over time and area figure out movement patterns even to the level of individual hardware.

Maybe I'm missing something but it does seem like a nice hack if a little overmarkted: It is technically unremarkable but clever and practical.

You can glance through the slides in a minute.