From the introduction
The characters are a mixed group of kids, old folks (called geezers), and thinking automatons (called Cogs), in a steampunk city named Tiran. These characters are vigilantes, but the criminals that they target are so much a part of the society of Tiran that they are often referred to as rebels.
Rebels usually operate in mixed groups, which are sometimes called crews. A rebel crew is considered "legitimate" by other rebels only if they have cleaned up a neighborhood and established a base of operations; the rebels which are being played in this game have already done this.