Train stations across the UK secretly used AI-powered cameras to monitor and analyse the ages, genders and emotions of travellers without their knowledge or consent.

According to documents obtained under a Freedom of Information Request, trials were conducted by Network Rail, the organisation responsible for rail infrastructure in the UK, at eight major stations including London's Euston and Waterloo, and Manchester Piccadilly, for two years. 

The systems used Amazon's Rekognition software to detect people trespassing on tracks, monitor platform crowding, identify "antisocial behaviour" such as running or smoking, and to spot potential bike thieves. The cameras were also used to predict travellers' emotions like happiness, sadness, and anger by analysing their facial expressions. 

The finding prompted concerns from civil rights and privacy advocates about Network Rail's lack of transparency and public consultation about the use of AI surveillance systems in public spaces, the inaccuracy of emotion recognition systems, and the potential misuse of personal data for purposes such as emotional profiling and targeted advertising.

Network Rail later denied using emotion recognition.