The UK plans to use a snoop-watch to track the movements of some convicted criminals, The system includes facial recognition to verify that the intended person is carrying the snoop-watch.

Since this system tracks and recognizes only a specific person, and is imposed on that person as part of punishment after conviction for a crime, it is one of the exceptional legitimate uses of facial recognition and location tracking.

This example also highlights, by the contrast it makes, the injustice of imposing facial recognition or location tracking on anyone other than a convict. They are typically imposed combinations of businesses that are so powerful that they can shape our society. They receive help from various laws designed to give those companies power.

Carrying a snoop-watch is easier than wearing an ankle-chain, and is much less painful than being in jail.