China's Health-Tracking QR Codes Expand Role, Raising Concerns

China’s health-tracking QR codes, which have played a key part in the country’s successful containment of the coronavirus, now look set to play a much broader role in daily life as local authorities dream up new uses for the technology. Embedded in the popular WeChat and Alipay smartphone apps, the codes use self-reported and automatically collected travel and medical data to give people a red, yellow or green rating indicating the likelihood of having the virus.