I suspect it won't be long before these kind of devices will be built into all cars before the leave the factory. Or for that matter,into all people, as a statutory implant.

And of course they'll say "if you aren't doing anything wrong you've no need to worry."

The so-called totalitarian societies of the past were primitive amateurs when it came to controlling the population. That's why they were so clumsy, having to go in for repression of people en masse. No need for that when you can target and pick off anyone you like as an individual, for whatever reason your particular regime might decide is unacceptable.