Big Brother is watching: Chinese city with 2.6m cameras is world's most heavily surveilled

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.