In January 2010, hundreds of illegal migrants took the streets of Rosarno (Italy), for a violent protest against the acts of racism which they ordinarily suffer. Their revolt is exceptional. A collective subject, considered “invisible,” dare to revolt. These migrants are an anomaly, in the social, legal, and political sense. In the social sense: since they are cast away from the society in which they live. A society that, at the same time, cannot exist without them, as they are the necessary – because the cheapest and the most subject to blackmail – labour-force. In the legal sense: since they do not have any legal protection against the impositions that they suffer. In the political sense: since they are supposed to access the political sphere only as victims whose misery can only be indirectly represented. Therefore, their revolt “interpellates” the political theory. In my paper, I will analyze a few categories of contemporary political theory such as the “bare life” of Agamben, and the “disagreement” of Rancière. I will show how these categories fail to interpret these phenomena. I believe that the Spinozist concept of indignatio is, on the contrary, a useful intellectual tool to interpret a phenomenon like the revolt of Rosarno. What happens when slaves rebel? What happens when the body – the ultimate resource of those who own nothing – is put forward on the political battle front? I wish to answer these questions, relating them to their philosophical background, with a special focus on Spinoza.