There have been quite a lot of protests over the last few years that have gone violent. G20, The Berkeley Milo Speech, The Free Speech Demonstrations in Berkeley, Ferguson, etc. I don't know what you call "small scale" but these events have had a substantial amount of brawling and property damage being done. Maybe not Rodney King level, but definitely noteworthy.

In many of those cases, it's far more than just a few bad actors. If you watched footage from the Milo event for example, the Antifa crowd had a lot of people out in force. Ferguson had a lot of out of towners come in to create trouble despite the locals trying to keep things calm.