When the man from Hangzhou returned home from a business trip, the local police got in touch. They had tracked his car by his license plate in nearby Wenzhou, which has had a spate of coronavirus cases. Stay indoors for two weeks, they requested. After around 12 days, he was bored and went out early. This time, not only did the police contact him, so did his boss. He had been spotted ... by a camera with facial recognition technology, and the authorities had alerted his company as a warning. I was a bit shocked by the ability and efficiency of the mass surveillance network. They can basically trace our movements ... at any time and any place," said the man, who asked not to be identified for fear of repercussions. Chinese have long been aware that they are tracked by the world's most sophisticated system of electronic surveillance. The coronavirus emergency has brought some of that technology out of the shadows, providing the authorities with a justification for sweeping methods of high tech social control. Artificial intelligence and security camera companies boast that their systems can scan the streets for people with even low-grade fevers, recognize their faces even if they are wearing masks and report them to the authorities. If a coronavirus patient boards a train, the railway's "real name" system can provide a list of people sitting nearby. Mobile phone apps can tell users if they have been on a flight or a train with a known coronavirus carrier, and maps can show them ... where infected patients live.