If power corrupts, whose power should we worry about most? Following a teleological rule of law conception focused on reducing the arbitrary exercise of power (Krygier), this paper argues that we need to focus on the consequences of arbitrary power for its subjects rather than assume that the rule of law applies to a specific category of actors. This paper focuses on transnational corporate actors, who exemplify the relevance of the analytical question about private power and its limitations. As part of the inquiry on the sources of such private power, the paper explores the function of the rule of law in both generating and mitigating private power. Furthermore, the absence of obvious resources for rule of law limits on transnational corporate power prompts the question of how to reconstruct the ideal of the rule of law to bring the power of private actors beyond the state within its scope.