Life in China is ruled by the government's COVID health app. That app is ripe for abuse.

In China, life is now governed by an official coronavirus health app on pretty much everyone's smartphones. More important than a passport, more personal than a photo, the app decides who can go where. It can force people to cancel trips, retreat into isolation, or even seek hospital treatment.

Not having it really isn't a viable option for most people in China. Without it, you can't even get to work.

Once downloaded, the software operates like a traffic light: Green means "safe from COVID," and allows the holder access to all buildings, including grocery stores and offices.