Now that's a pretty insensitive sign. You don't think that someone with a different view than the protesters would act like they are one of the protesters and try to make them look bad with a sign like that do you?
I absolutely think it is a plant. It is far easier to do this when they are wearing a mask. Note that those without the masks are holding the flag because they care about America. No one protesting for the freedom to move around is asking to kill anyone.