In this Article, I demonstrate that anonymity has been misconceived as an aspect of privacy, and that understanding this mistake reveals a powerful and underutilized set of legal tools for facilitating and controlling the production of information and other social “goods” (ranging from uncorrupted votes and campaign donations to tissue samples and funding for biomedical research). There are three core components to this analysis. First, I offer a taxonomic analysis of existing law, revealing that in areas ranging from contract and copyright to criminal law and constitutional law, the production of information and other goods is being targeted by three types of anonymity rules—rules that make anonymity and non–anonymity into rights, conditions of exercising rights, and most surprisingly, triggers that extinguish rights. Second, I propose a theory that makes sense of our law’s uses of these rules, identifying a cohesive set of functions that they perform across three phases in the production of a good: its creation, evaluation, and allocation. Third, I use my taxonomic and theoretical analysis to develop generally applicable lessons for the design of law and policy. Applying these lessons to a set of difficult and pressing questions concerning the production of specific biomedical and democratic goods, I demonstrate that they reveal innovative solutions that balance a wide variety of important and conflicting interests and concerns.