Sainsbury's staff eject wrong shopper after facial recognition alert – again

UK supermarket giant Sainsbury's temporarily suspended live facial recognition (LFR) at one of its stores after staff wrongly ejected a shopper in response to an alert – the second such incident this year.

Matt Arnold, 46, was ejected from the chain's store in East Dulwich, London, on August 6 after staff responding to a Facewatch LFR alert apparently mistook him for a suspected thief.

The comedy promoter told the BBC that he was using a self-service checkout and called an assistant over to approve an alcohol purchase.

Instead, two Sainsbury's managers approached him, refused to serve him, and linked him to an incident earlier that week.

Arnold said he was told that the store's LFR system had identified him in connection with a previous offense before he was escorted from the premises.

"They came over and said I had to leave," Arnold told the broadcaster.

"The staff member said I'd been identified by the AI, and the cameras had flagged me.

"A shoplifter does not walk around with that much shopping, they don't scan it through, they don't put their Nectar card through.

"But what upset me was thinking this is what the future could be – people just listen to what the machine tells them to do without thinking about the consequences." Sainsbury's told The Register that the mistaken ejection resulted from human error rather than a false match by the Facewatch system.

A spokesperson said: "We have contacted Mr Arnold to apologise for his experience at our Dulwich superstore.

"The incident was caused by human error, not the facial recognition technology.

Customers can be reassured that the Facewatch system has a 99.98 percent accuracy rate, and every match is reviewed by a trained manager." A Facewatch spokesperson likewise said: "We can confirm that our live facial recognition technology was not at fault in this incident.

A correct alert was sent to the retailer, but was subsequently subject to human error in the way it was handled and communicated by the retailer." We asked Sainsbury's what exactly the human error was in this case, but it did not reply.

The Register understands, however, that Arnold's ejection was similar to that of Warren Rajah, who was wrongly removed from the chain's Elephant and Castle store earlier this year.