I'm sort of baffled by your reasoning. You believe that they are "harming" the people by protesting with them?

I mean honestly, you think that one hour (not several hours as you posted) of protesting to show solidarity with the people being detained. One hour of looking the people you are trying to help in the eye and saying "We're with you! You are not alone." is somehow "harming" the people they're trying to help?

Maybe you feel that you can save the world behind a keyboard but most of us would, I think, disagree. You have to show support with actions, not just words.

I think the choice of actions matters too. If people aren't going to think seriously about the consequences of their actions instead of just going along for fear of being branded strikebreakers, I'd rather they limited themselves to words. At least that way they won't cause that much damage.

No opinion on the specific case, I just find your proposal overbroad.