Some instances of right and wrongdoing appear to be of a distinctly collective kind. When, for example, one group commits genocide against another, the genocide is collective in the sense that the wrongness of genocide seems morally distinct from the aggregation of individual murders that make up the genocide. The problem, which I refer to as the problem of collective wrongs, is that it is unclear how to assign blame for distinctly collective wrongdoing to individual contributors when none of those individual contributors is guilty of the wrongdoing in question. I offer Christopher Kutz’s Complicity Principle as an attractive starting point for solving the problem, and then argue that the principle ought to be expanded to include a broader and more appropriate range of cases. The view I ultimately defend is that individuals are blameworthy for collective harms insofar as they knowingly participate in those harms, and that said individuals remain blameworthy regardless of whether they succeed in making a causal contribution to those harms.