I haven’t really followed most protests in a while, but I do recall more than a few occasions where there was a particularly hot-button issue being protested by two separate groups in close proximity and the police were there solely to keep the different protesting groups away from each other. I seem to remember that they (the protesting groups) had gotten a bit rowdy but that not much came of it.

The riot squads committing war crimes against civilians stick out in part because of the brutality but also because of the relative rarity of it.