British Transport Police (BTP) spent more than £320,000 putting half a million commuters through live facial recognition cameras, only for the system to identify precisely nobody it was looking for. Figures obtained by civil liberties group Liberty through Freedom of Information requests, and reported by The Guardian, show BTP’s six-month trial scanned more than 500,000 faces at London railway stations and generated just one alert. That turned out to be a false positive, meaning the technology produced no correct matches and no arrests directly resulting from an LFR alert. The exercise wasn’t exactly light on resources either. According to the figures, deployments swallowed almost 100 hours of police officers’ time and cost more than £320,000. Privacy campaigners at Big Brother Watch told The Register the results would be funny if the implications weren’t more serious. “The figures from the British Transport Police’s live facial recognition pilot would be laughable, if they didn’t have such troubling implications for our rights and freedoms,” said Jasleen Chaggar, senior legal and policy officer at the campaign group. “Millions of Londoners use the city’s stations every day and may have already found themselves caught in a digital police line-up, likely without even realizing.” Then there’s the small matter of what taxpayers got for their £320,000. “It’s not fair to subject innocent people to intrusive identity checks during their commute, but it’s even more insulting to waste almost 100 hours of officers’ time and £320,000 of public money when it produces such meagre results,” she said. “The pilot figures show that replacing officers with AI surveillance does not improve Londoners’ safety and British Transport Police should drop their use of live facial recognition.” But BTP isn’t dropping it. In fact, the trial has been extended until November and expanded from Network Rail stations onto the London Underground. The system uses NEC’s NeoFace M40 facial recognition tech, and cameras scan people passing through a designated area, comparing their faces against a police watchlist. When the software thinks it has spotted someone on that list, it generates an alert for an officer to review before deciding whether to stop the person. BTP says it cannot identify people who aren’t on a watchlist and that it immediately deletes their biometric data. It also says deployments are intelligence-led and targeted at crime hotspots where officers believe “high harm offenders” are likely to pass through. That claim of a targeted approach isn’t convincing everyone. Sarah Simms, senior policy officer at Privacy International, told The Register the results of the trial show just how many innocent passers-by can have their faces processed along the way. “We are deeply concerned by the results of the British Transport Police’s live FRT trial. It reaffirms how invasive and disproportionate live facial recognition tech is and why it shouldn’t be permitted. Thousands of people have their highly sensitive facial data processed in public spaces as they go about their daily lives, sometimes unknowingly. It also undermines claims of it being a targeted measure.” Simms also pointed to the lack of legislation specifically governing the technology as BTP continues to expand its use. “What’s further concerning is that they continue to extend these deployments when there is no specific legal framework in place to regulate facial recognition, which is essential to ensure there are restrictions and safeguards on its use to protect people’s rights,” she said. Those assurances haven’t put the wider controversy around police facial recognition to bed. Earlier this year, UK police temporarily suspended deployments after independent testing raised concerns about racial bias at some operating thresholds. BTP’s own experiment has produced a rather different problem so far: after scanning more than half a million faces, the only person its cameras picked out was the wrong one.®