A Theory of Power, Jeff Vail's Critique of Hierarchy & Empire: "Swarming, Open-Source Warfare and the Black Block"
Great reference in case you need to counteract a violent attack: 3 key principles:
1. Elusiveness, in the form of mobility or concealment
2. Standoff Firepower, relative to the opposing force
3. Situational awareness of the local environment, relative to the opposing force