@hikerus The Terms of Service may provide justification for an admin banning a user, but another instance with different ToS may not be compatible with my instance's ToS, and any federated messages originating on one instance may violate the ToS of another instance. Never mind that most people don't read the ToS anyway, so even a local user on my instance can post content contrary to my ToS. And that content can federate to other instances, where I no longer control that content, even though it originated on my instance. In a jurisdiction like Germany where there *is* such a thing as illegal content and the admin is responsible for any content stored on or originating from his server, it is crucial to have a technical means to enforce the ToS. Such technical means could be required by law (think of DMCA in the US, and Canada's Copyright Act). But even if the code has a technical means to enforce the law and ToS, with Free Software someone else can remove that code and run an instance with "illegal" code.