2 hours agoBy James Clayton,BBC NewsnightBBCSara needed some chocolate - she had had one of those days - so wandered into a Home Bargains store."Within less than a minute, I'm approached by a store worker who comes up to me and says, 'You're a thief, you need to leave the store'."Sara - who wants to remain anonymous - was wrongly accused after being flagged by a facial-recognition system called Facewatch. She says after her bag was searched she was led out of the shop, and told she was banned fr...