It's a curious analogy because in many contexts, use of a megaphone is quite abusive warranting confiscation. If I attend a political rally and the speaker use

It's a curious analogy because in many contexts, use of a megaphone is quite abusive warranting confiscation. If I attend a political rally and the speaker uses a megaphone, that's fine, I have consented to it's use. However other places I have witnessed their use has questionable legality due to breach of the peace because the audience has not consented e.g. getting heckled when entering a University site or getting assailed by someone promoting their batshit Christian cult when trying to do some shopping. I don't think anyone would assume a universal right to make unwanted amplified noise.