Still on the fence about that Faraday bag?

Tell me again how this will only be used for Amber Alerts and finding stolen cars...
Turning Bluetooth off does not stop it from emitting a signal.
A surveillance company (Leonardo) is developing
SignalTrace, an add‑on for ALPR cameras that:
- Scans for Bluetooth device identifiers
- Detects phones, AirPods, smartwatches, fitness trackers, vehicle infotainment Bluetooth IDs, etc.
- Correlates those device IDs with specific license plates
- Builds a pattern of which devices regularly travel with which vehicles (suggests that to "build a pattern" data might have to be collected over time, longer than the 30 day retention period Flock claims)
- Allows law enforcement to identify drivers and passengers, not just cars
A surveillance company plans to add sensors to automatic license plate readers (ALPRs) that would mean the devices, as well as capture the license plate of passing vehicles, would also sweep up unique identifiers of mobile phones, wearables, and other Bluetooth-enabled devices in those cars, potentially letting law enforcement identify specific drivers or passengers.
The technology, called SignalTrace, would turn ALPR cameras from devices focused on tracking cars to ones that can more readily track the location of particular people. ALPR cameras have become a commonly deployed technology all across the U.S.; SignalTrace would make some of those cameras capable of collecting much more data.
Correlation with license plates
This is the big leap:
The system links
device → person → car.
Traditional ALPRs track
vehicles.
SignalTrace would track
people.
That’s a fundamental change in surveillance capability.