How China uses a mass surveillance phone app to track its citizens

A mobile app used by police to track citizens in China’s far west region of Xinjiang shows how some of the country’s biggest technology companies are linked to a mass surveillance system that is more sophisticated than previously known, according to a report from Human Rights Watch.

The app uses facial recognition technology from a firm backed by Alibaba Group Holding to match faces with photo identification and cross-check pictures on different documents, the New York-based group said on Thursday. The app also takes a host of other data points -- from electricity and smartphone use to personal relationships to political