'Respectful' is not a requirement for peaceable assembly granted by the US Constitution.

You have every right to dislike him for it, but calling it un-American couldn't be further from the truth.
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She was standin' alone over by the juke box, like she'd something to sell.
I said "baby, what's the goin' price?" She told me to go to hell.

Bon Scott - Shot Down in Flames