I disagree with the notion that violence is by definition counter productive in contrast to protesting peacefully in the modern world.
The whole reason strikes work is because they are costly to the capital owners, and threaten even more cost, ongoing cost, but with robots replacing everyone that power is undermined. Strikes aren’t really peaceful, they are a threat.
Peaceful protest is the illusion of power. It might as well be an angry letter for all the good it does. An effective protest on the other hand is by definition a credible threat. That’s why they work better when huge, depending on the power of the opposition. But if a protest is committed to peaceful conduct and the authorities know that, then the threat has no credibility and no concessions will be made. Proof: The Iraq War Protests: Worldwide, Huge, Absolute Failure. Occupy Wallstreet: Peaceful. Failure.
As for looting: Most people live in debt and thus don’t own anything really. Neighborhoods are owned by speculator land lords and other capitalists. So when the owners make life hell, burning their profit margin to the ground is legitimate and effective as far as I can tell. Only power is relevant. And the only reason the people ever got respect is the threat they collectively represent.
In today’s context, anti-police riots, attacking property creates opportunity to document over-policing, which police then GREEDILY SADISTICALLY pounce on, which in turn gets more publicity and fuels more protest, and thus we inch closer to social reform, as the threat of civil war escalates. This fear is what drove the entire cold war era. The plutocrats are terrified by the notion of revolt.

When the President puts up a 10 ft fence around his house you know your threat is credible. This would not have happened with a purely peaceful protest.
Peaceful protest alone accomplishes nothing in the modern world. Force underwrites all reform, good or bad. The only reason democracy evolved is because of the violent potential of the masses. It’s written into the very fabric of reality. It’s as hard and cold as mathematics. Two working together is worth three working apart.
A huge protesting mob working in unity is Dangerous, and that’s the ONLY reason they ever make progress.
“See? Now you respect me, because I’m a threat.”
Syndrome, The Incredibles