The Dukes generally do a good job of crushing peoples’ spirits. They’re experts at it. But nothing seems impossible with a few pints of ale in you, especially when fired up by a particularly good game of darts, or perhaps a really good seminar on early twentieth century revolutionary discourse. Thus even the most downtrodden of people are occasionally inspired to march right from the tavern near closing time up to the forbidding obsidian gates of their oppressors, hurling epithets, hurling cobblestones, and occasionally just hurling into the gutter.
The Angry Mob knows what it wants: JUSTICE! And it knows when it wants it: NOW! However the Mob isn’t too clear on what Justice is, or how throwing stones and brandishing torches will accomplish Justice, or whether Justice can rebuild a crumbling civic infrastructure, or pay off student loans. When you get right down to it the Angry Mob isn't even sure which set of forbidding, obsidian gates they should be protesting in front of. Fortunately for them, in this world, pretty much everyone with any wealth or power ranks high on the Index of Evil. In other words, they can't go wrong.
The Mob isn’t very effective against actual soldiers, but they do fine against the equally drunk but much less righteous Riff-Raff.