[jlawson]

>"the virus 2 microns. too small for masks to capture."

This is literally true; it's just incomplete given the relationship with saliva as you noted.

The solution here is to reply and spread more true knowledge.

You can cite super-narrow cases constructed to make censorship seem like a great idea. Within the limited bounds of those examples, the argument may seem to hold water. But in reality, there is no way to limit the power of censorship to the places where it's right to use. It will always be abused, and today it is being abused massively to suppress reasonable ideas from millions of people because they don't flatter the values of the people who happen to hold power.