Uhh, I read what you wrote. Come up with a better example then. I may be talking past you but you seem to agree with the minority, so I'm trying to coax out some extra defense, since your metaphor is flawed.

KD already said it, but I'll paraphrase. Speech is only regulated when the effects of the speech itself is unlawful or is intended to incite unlawful behavior. That's why the megaphone is banned, it violates other's rights, you acknowledge it's a broken metaphor anyway.

The placement of TV ads on private TV stations that plainly advocate something (buy this, support this political viewpoint) is not one that should be regulated by the government.

Local governments could try to pass restrictions but the 1st Amendment would seem to win. And Congress is explicitly barred from attempting to try.