How Does Protest Create Change?

What's the purpose of protest? What does it achieve? Is a cause-inspired protest too easily hijacked by important - but ultimately unrelated - right-wing or left-wing causes? What motivates people to protest? Are there ways to advocate for change apart from speechifying, flag-waving and public disruption? Consider these and other important questions this coming Tuesday; buy a drink at the bar @ Walters and add your voice to the civil discourse that is Socrates Café.