This thesis uses a systemic deliberative democracy framework to evaluate responses to misinformation along the actors, behaviours, content and diet vectors. In stemming the tide of online falsehoods, we can aim for a system that provisionally recognizes diligent reporting and gives credit to social discovery,shielding it from both domination and manipulation, while ensuring that popular claims are properly scrutinised and demanding for citizens an opportunity to consider multiple sides of an issue. Digital platforms provide scalable infrastructure, yet scarce attention and moderation resources to their users, communities and business partners. They are caught in a web of conflicting demands to regulate their complementors, some of whom push back by enlisting public opinion, the state and other platforms. Influential industries want a better bargain and partisans seek to pre-emptively defang platforms. The latter in turn bestow privileges and rule-exemptions, while pursuing collaboration amongst themselves and external alliances. Nevertheless, I argue that the platforms’ infrastructural and regulatory roles can be harnessed towards better deliberative outcomes. I followed emerging networksthat seek to engage and countervail platform power: journalists setting up credibility initiatives, or pivoting to independent fact-checking, and researchers chasing platform manipulation. They promote the public interest, embracing clear standards and open membership. I suggest two existing platform practices, tiering and tethering, for public regulation to reshape. Tiering means distinct regimes for different on-platform actors. I argue tiers can play complementary deliberative roles, for instance pairing inclusive content to epistemically valuable scrutiny. Modelled on tripartism, tethering should link platforms to independent networks, providing complementary discursive justification and insulating platforms from hegemonic demands. In return, these networks carve an area of self-governance independent from platform power. I discern a double gateway channelling platforms’ experimentation with technical and design solutions together with independent domain expertise and dedication towards discursive justification.