thought I recognised the face

> Customers can be reassured that the Facewatch system has a 99.98% accuracy rate, and every match is reviewed by a trained manager.

That's not "reassuring" at all. If Sainsbury's gets, say, 10M customers per week, then that means 2,000 people per week are being falsely accused.

Likewise, if you visit Sainsbury's twice a week for groceries, the odds are favorable that at some point in your life you will be falsely accused, even with a 99.98% accuracy rate.