Year-on-year deployment isn’t really a trial, say privacy groups <https://www.theregister.co.uk/2017/08/17/concerns_over_facial_recognition_at...> London's Metropolitan Police have been urged to back down on plans to once again use facial recognition software at next weekend's Notting Hill Carnival. Privacy groups including Big Brother Watch, Liberty and Privacy International have written to police commissioner Cressida Dick <https://www.liberty-human-rights.org.uk/sites/default/files/Joint%20letter%2...> (PDF) calling for a U-turn on the use of the tech. Automated facial recognition technology will snap the party-goers' faces, and run them against a database. The aim is to alert cops to people who are banned from the festival or are wanted by the police, presumably so they can take immediate action. The tech was first tested at the festival – where relations between police and revellers are often strained – last year <https://www.theregister.co.uk/2016/08/26/notting_hill_carnival_police_survei...>, but it failed to identify anyone. Despite this, the Met said at the time <http://news.met.police.uk/news/statement-from-police-commander-for-notting-h...> that it had "resulted in positive learning" and is describing this year's use as a continuation of the trial. It also said in a statement sent to /The Register/ that there would be a public consultation after the trial is complete. But the privacy groups' letter said that they "reject the notion that year-on-year deployment constitutes a 'trial' – for which, by the Force's own admission, there are 'no timescales'". The letter also points to reports of inherent biases in the system – research has previously shown <http://ieeexplore.ieee.org/document/6327355/> that matching accuracies are lower on certain cohorts of people: women, black people, and those aged 18-30. "Notting Hill Carnival is an event that specifically celebrates the British African Caribbean community," the letter states. "We reject the proposition that it is appropriate to test biometric surveillance on this community." [...]