> Protests should be allowed
They are.
> destroying public property
Is illegal and you can be arrested for it.
> advocating violence or hate
Is illegal and you can be arrested for it.
You just can’t be arrested for “being rude”. You have to commit a crime.
Protesting does not mean you’re immune to prosecution for non-free-speech crimes. What happened with the BLM riots was simply governments deciding, for one reason or another, not to stop the crimes being committed.
> Is illegal and you can be arrested for it.
This is untrue. Immediate, direct, actionable threats are illegal, saying "I/we/you need to go hunt down and murder X now" can be construed as an actionable threat.
Extolling the virtues of murder and opining about how nice it would be if someone finally hunted down and killed X is legal free speech.
You can talk about how X needs to die all you want, but if you start making immediate, direct, actionable threats towards X, that crosses territory from free speech to illegal threats.
Various circuit courts have different tests for what constitutes a true threat versus legal free speech, some of which can be found here[1].
For example, here's the 2nd Circuit's opinion:
> a true threat is “on its face and in the circumstances in which it is made is so unequivocal, unconditional, immediate, and specific as to the person threatened, as to convey a gravity of purpose and imminent prospect of execution.”
[1] https://mtsu.edu/first-amendment/article/1025/true-threats
Protests should be allowed, but it's not an absolute god given right - if you're being a dick, destroying public property, advocating violence or hate - then no, you shouldn't be allowed to protest. I know in America you let even neo nazis march your streets and boast how that's "freedom" but that's not freedom - that's blindly following certain ideology(freedom to do anything AT ALL costs) without any consideration as to what that does to your society.