[Digit-Al]

There is one potential way it may be getting used which would probably be legal.

Years ago, before smart phones became ubiquitous, I worked for a company that had a contract to provide kiosks containing travel planning software to bus and rail stations. As part of this, one of the jobs I had to do was create a method of recording information from an onboard camera in the case of the kiosk being vandalised.

How it worked is I made a rolling cache of the last 30 seconds of video; this was never saved unless an onboard "shock sensor" was activated. If the shock sensor was activated then I would save the last 30 seconds of video plus another minute or so. This could then be used as evidence by the police to help catch the vandals.

I have no insight into how the Sentry Mode functionality works, but it could very easily use a similar sensor to car alarms to only actually save the recorded video if there is some sort of "impact" on the car.