Was this the behaviour of peaceful protesters?

To be fair, the police do attack protestors. If I ever went out to protest, I'd dress similarly and have a riot shield.

Police in the Netherlands don't use violence unless in defence of innocent bystanders or themselves. That's different in the USA? Isn't the crede 'to protect and serve' instead of 'attack and try to kill'?

It's way different in the USA than it is from anyplace in the world that isn't a despotic regime.

Ever see the movie, Gangs of New York?
It literally started there, in the Five Points neighborhood.
It was so violent, cops eventually had to start carrying guns, and so it spread throughout the US from that, with policing being a more aggressive action,,,

Then after 9/11, they started getting military equipment and training, so now their tactics can be far more paramilitary.

Clearly, the answer depends on which group is doing the protesting, and which media organization is doing the reporting.

Too bad there can't be an objective, consistent standard to answer a simple question like that.

200k women and men marched in DC in 2017, protesting trump after his inauguration, not one weapon or piece of body armour.