On London’s streets, live facial recognition tests the balance between security and liberty Sign up now: Get ST's newsletters delivered to your inbox LONDON – Tourists, shoppers and office workers on a busy London street on an ordinary weekday found themselves part of a digital identity check as live facial recognition cameras scanned faces against a police watch list. The operation was an example of a technology that the Metropolitan Police say is transforming policing, helping officers arrest around 2,500 wanted people since the start of 2024, including suspects accused of violent and sexual offences. Critics, however, say live facial recognition undermines the presumption of innocence underpinning British law by treating every passer-by as a potential suspect. A court challenge brought by civil liberties campaigners and a community worker who had been wrongly identified failed in April, clearing the way for the technology’s expanded use. In Victoria, central London, on a recent Monday, few people appeared concerned by the temporary cameras, a police van and signs warning that live facial recognition was in operation. Within an hour, the system alerted an officer in the control van to a possible match. Local officers approached a man and questioned him briefly before letting him go. Police later said the alert related to court-imposed restrictions rather than an arrest warrant. About 30 minutes later came a second alert. A man in a grey hoodie, black baseball cap and blue trainers looked startled as two officers stopped him on the pavement. He was handcuffed and waited beside the road until a police van arrived to take him into custody. Police hail ‘groundbreaking’ technology Met Police director Lindsey Chiswick, who is the national and Met lead for live facial recognition, said the impact of the technology has been groundbreaking for policing in the capital, helping