London’s Metropolitan Police used live facial-recognition cameras at the Notting Hill Carnival over the weekend, marking one of the largest deployments of the controversial technology in Europe. Cameras were positioned at key entrances and exits to compare revellers’ faces with thousands of images on police watch-lists. The two-day Caribbean cultural festival, which draws about two million people, recorded 140 arrests on its first day — a 40 percent increase on last year — for offences ranging from assault on officers to weapons possession. The carnival operation forms part of a wider national rollout. Police chiefs say the real-time system has contributed to more than 1,000 arrests across the United Kingdom since the start of 2024, after roughly 4.7 million faces were scanned last year. The Home Office has authorised seven more regional forces to adopt the technology and plans to install Britain’s first permanent street cameras in Croydon, south London, next month. Civil-liberties groups warn that Britain risks becoming a “nation of suspects”. Big Brother Watch, Liberty and eleven other organisations wrote to Met Commissioner Mark Rowley urging him to halt the carnival deployment, citing legal uncertainty, potential racial bias and the absence of specific legislation. The Equality and Human Rights Commission has also questioned the Met’s policy, calling it incompatible with human-rights standards. Real-time facial recognition is effectively banned in the European Union except for defined security threats, making the United Kingdom an outlier among liberal democracies. Home Secretary Yvette Cooper has promised to draft a statutory framework focusing on serious crime, but critics say any law must include stronger safeguards on data retention, transparency and independent oversight before the cameras become a permanent feature of British streets.