While rioters may claim to work on behalf of protesters and challenging an oppressive political regime, their destruction of property and businesses do not send a message of revolutionary change. Instead, riots bring more attention to the violence rather than the legitimate requests and grievances of the political movement.
Media attention will focus on protesters' violence rather than on instances of democratic negotiation or positive change that result from a peaceful protest. Instead of promoting political change through civic discourse, riots call attention to the need for law and order enacted by the ruling class, not the need for systematic change.
In a democratic society, rioting and violence cannot be justified because rioting disrupts the social contract between the government and its citizens.
Citizens must use civil means to enact change, whether voting, petitioning, or organizing a community dialogue.