Social media ‘back in the hands of the people’? Nuancing assumptions of legitimate content moderation on Mastodon

A series of controversies have plunged large social media platforms into a perennial legitimacy crisis, fuelling interest in noncentralised digital spaces. In particular, the Fediverse has come to embody hopes that online speech governance can be more democratic and legitimate. This article examines this possibility by exploring how content moderators on Mastodon, the most prominent Fediverse service, negotiate their political legitimacy. Drawing on political philosophy and in-depth interviews, we demonstrate that this negotiation depends on how these individuals conceptualise their communities (‘instances’) as polities. These perceptions exist on a scale between viewing instances as bottom-up participatory spaces – broadly aligned with a democratic view of legitimacy – and as top-down governable spaces, reminiscent of aspects of an authoritarian understanding of legitimacy. By complicating the assumption that decentralisation necessarily returns social media to ‘the hands of the people’, the article also interrogates the role of technological design in shaping online political culture.