As China encourages people to return to work despite the coronavirus outbreak, it has begun a bold mass experiment in using data to regulate citizens' lives - by requiring them to use software on their smartphones that dictates whether they should be quarantined or allowed into subways, malls and other public spaces. The system does more than decide in real time whether someone poses a contagion risk. It also appears to share information with the police, setting a template for new forms of automated social control that could persist long after the epidemic subsides. The Alipay Health Code, as China's official news media has called the system, was first introduced in the eastern city of Hangzhou ... with the help of Ant Financial, a sister company of the e-commerce giant Alibaba. People in China sign up through Ant's popular wallet app, Alipay, and are assigned a color code - green, yellow or red - that indicates their health status. The system is already in use in 200 cities and is being rolled out nationwide, Ant says. As soon as a user grants the software access to personal data, a piece of the program labeled "reportInfoAndLocationToPolice" sends the person's location, city name and an identifying code number to a server. The software does not make clear to users its connection to the police. In the United States, it would be akin to the Centers for Disease Control and Prevention using apps from Amazon and Facebook to track the coronavirus, then quietly sharing user information with the local sheriff's office.