Yes, you do need to authenticate before joining a privately hosted server, unless you change 'online-mode' in server.properties in the server folder. This came

Yes, you do need to authenticate before joining a privately hosted server, unless you change 'online-mode' in server.properties in the server folder. This came with a few issues. Offline servers usually had a plugin which let you create a password connected to your name in-game, since anyone in theory could just change their name to yours and get your inventory and permissions, including OP. AuthMe is an example of an authentication plugin, if you're interested in checking it out. So central authentication has been a part of the game since the beginning of multiplayer more or less, but Microsoft has taken it quite a bit further with the recent changes. Quite a shame to potentially be banned from a private server I host myself, whitelisted only for IRL friends. How strict the criteria to actually get banned is irrelevant in my opinion, I bought the game over ten years ago, and now suddenly risk losing access to multiplayer, which was the only reason I bought the game. But we'll have to see how it actually gets implemented, I really hope it's opt-in, or at the very least possible to opt out for privately hosted servers, but I have no issue with it being implemented on Realms.