I have a Blackvue camera, and just checked the settings. I don't think I've looked at it before when setting it up, but it seems to be defaulted to off. You have to opt in to this. I'm not sure why anyone would. Maybe to attempt tracking your car if it gets stolen? I'd be pretty easy for any thief to thwart by unplugging the camera, but in the heat of the moment they might miss it.
Or maybe it's for those vain idiots that constantly broadcast their lives as if anyone else gives a fuck, in which case I hope they get everything they deserve.