Scholars in sociology, criminology, and political science have long recognized that vigilantes emerge within communities, monitoring for and punishing deviance without formal authority to do so. Recent descriptive research also suggests that vigilantes can emerge in workplace communities, and that many people over the course of their careers report having worked with at least one vigilante. However, we presently have little understanding about the organizational factors and psychological mechanisms that explain why employees become vigilantes. In this paper, we propose a theoretical model specifying the antecedents of adopting the workplace vigilante role identity. By doing so, we introduce organizational and psychological conditions that could lead employees to administer unauthorized punishment as a means for exercising social control over their coworkers.