Social media platforms such as Facebook, Twitter/X, or TikTok are controlled by and rely on a single service provider. However, repeated controversies around data breaches, algorithmic bias, or misinformation have eroded trust in these centralised platforms. Concurrently, advancements in blockchain technology have opened avenues for decentralised social media that distribute control and data across a network of participants, thereby challenging their centralised counterparts. This study reviews existing literature on the topic and finds that what we know largely focuses on the technological implementation of decentralised social media. Therefore, we surveyed the literature for socio-technical dimensions of the phenomenon and found that control, privacy, operation, security, rewards, adoption, and research are central themes in this regard. We use those themes to derive recommendations for future research in Information Systems (IS) and beyond that aims to unpack individual, organisational, and societal implications of decentralised social media.