Qiu Rui, a policeman in Chongqing, was on duty this summer when he received an alert from a facial recognition system at a local square. There was a high probability a man caught on camera was a suspect in a 2002 murder case, the system told him.
The depth, breadth and intrusiveness of China's mass surveillance may be unprecedented in modern history
The city’s surveillance system scans facial features of people on the streets from frames of video footage in real time, creating a virtual map of the face. It can then match this information against scanned faces of suspects in a police database. If there is a match that passes a preset threshold, typically 60% or higher, the system immediately notifies officers. Three days later the police captured the man, who eventually admitted that he was the suspect.
Cases such as this, where facial recognition systems are used to help local police crack crime cases, are not unusual in the south-west China city, which recently ranked first in an analysis of the world’s most surveilled cities compiled by the UK-based technology research firm Comparitech. With 2.58m cameras covering 15.35 million people – equal to one camera for every six residents – Chongqing has more surveillance cameras than any other city in the world for its population, beating even Beijing, Shanghai and tech hub Shenzhen.