This is obviously different in countries that are not free.
So… the US? People are regularly arrested for perfectly legal, not even a shadow of a doubt, activity at protests. And protesters are vulnerable to not just cops, but dangerous actors who support the thing they’re protesting against. Whether it’s doxing, billionaire-funded slander, your boss not liking the cause, or actual violence, there’s plenty of reason not to want your face to be easily identifiable, even while orderly protesting for a just cause. Never mind health concerns like not wanting to catch COVID (or breath tear gas).
The idea that orderly protesting is safe in the United States is incredibly naïve.
At this point in time, I do not see the US as a free country in this context.
This is a story about protests and mask bans in the US and non-governmental actors can still be a threat to protesters in a “free” country.