Violent protest is the dictatorship of the individual. It begets the tyranny of the state. Confronted by violent citizens, government introduces more restrictive law, and tougher military policing, which the media and silent majority approve. The underlying issues are ignored and public debate refocuses around points of law and order.
Democracy narrows and the rights and opportunities of aware and active citizens shrink.
This law of revolutionary consequence happens as easily in mature, as in fledgling, democracies. These illiberal laws block much significant democratic challenge to government and companies. What the hot-heads have to understand is that you don't need violence to win, at least not in a democratic, regulated market economy. Companies do not make products that consumers ignore. No bad company practice can withstand the challenge of media expose, preventative laws or tax regimes, or shareholders dumping stock in protest.