I think it also shows they themselves know what they’re doing is wrong. They know their current bosses and political leaders agree, they don’t have to fear them in any way. They do it because it protects them from hysteric parents or angry mobs, but I think they most of all do it because theyvdont want there to be any evidence (= footage showing them doing this). This is not like people hiding their identity during a protest, this is like people hiding their identity when robbing a bank.