Starting from the increasing awareness of the necessity to regulate social media’s activity in content moderation, in this article I try to frame the peculiar model embodied by the Facebook Oversight Board. The conflicts that arise from social media are all too relevant in the light of the pro- tection of fundamental rights. Therefore, assessing actors and procedures involved in content moderation is crucial for shaping the founding principles of digital constitutionalism – a process aimed at protecting fundamental rights through the limitation of emerging private powers on the web.In this perspective, FOB represents an excellent case study: it entails a brand-new model of content moderation which raises several questions, both related to its con- textualization within legal categories as well as its consistency with legal and democratic standards. After having described FOB’s design – in terms of rules, functions and procedures – I classify FOB in the alternative between contractual means of dispute resolution and a company’s internal complaint-handling process. Subsequently, I try to contextualize FOB within the legal framework provided for by the Digital Service Act proposal of the European Union. Lastly, I answer the question this paper moves from, i.e. the compatibility of the institutionalization of private adjudication with digital constitutionalism’s goals.