When you unlock a phone, step into view of a security camera or drive past a license plate reader at night, beams of infrared light - invisible to the naked eye — shine onto the unique contours of your face, your body, your license plate lettering. Those infrared beams allow cameras to pick out and recognize individual human beings.
Over the past decade, facial recognition technology has gone from science fiction fantasy to worldwide reality — nowhere more so than in China, home to more security cameras than the rest of the world combined.
At airports and train stations, passengers line up for face scans at gates and by officers.
On the streets, cameras scan pedestrians and flag vehicles breaking traffic rules.
By law, anyone registering new SIM cards in China must show themselves to a face scanning camera, the images stored in telecom databases. And until recently, Chinese authorities required most guests to scan their faces when checking in to a hotel.
For many, such technology has offered convenience and safety, seamlessly woven into the backdrop of their lives. But for some, it's become an intrusive form of state control.
Associated Press investigations have found that such surveillance systems in China were to a large degree designed and built by American companies, playing a far greater role in enabling human rights abuses than previously known. It has cemented the rule of China's ruling Communist Party, offering it a powerful tool to control and monitor perceived threats to the state like dissidents, ethnic minorities and even its own officials.
Dozens who spoke to AP, from Tibetan activists to ordinary farmers to a former vice mayor, described being tracked and monitored by vast networks of cameras that stud the country, hampering their movements and alerting the police to their activities.