> Cf the present day Hong Kong protests, and Yellow Vests protests - in both cases, the government would use snooping power to spy on the communications, dragnet style.

The USG has been working quite diligently on that already. I don't think there's any particular reason to believe it can't read (almost?) any email it wants to. Very few emails are encrypted and host-to-host encryption is optional anyway. Various providers that have tried to resist USG secret warrants have just given up because it's not really possible.