Social media covers platforms where people and organisations publish posts and media, follow each other and form communities, including federated and self-hosted networks. Organisations use them to communicate with customers and citizens, to recruit, to build communities and, in some cases, as internal social networks.
The sovereignty issue goes beyond data protection. A platform decides who sees what, can change its terms or algorithms overnight and can close an account with limited recourse. Your audience, content and engagement history live inside that platform, so moving them is hard even where export tools exist. The Digital Markets Act places obligations on the largest platforms, but it does not give you control over where your data sits or who ultimately owns the service.
When looking at a European option, consider the governance model (company, foundation or federated network), whether it uses open protocols such as ActivityPub, how moderation and appeals work, and what the business model is. Check whether you can export posts, followers and media in a structured format, and whether you can redirect your audience to a new address when you leave.