It’s one of the largest social control experiments ever anywhere, even in China. To do it, Beijing is relying on local party officials, police, and busybodies known as grid workers. They’ve effectively closed down many cities to outsiders. This is a station at a closed city: Yiwu pic.twitter.com/9x27uDjxHI— Paul Mozur 孟建国 (@paulmozur) February 15, 2020