If they wanted privacy they could just set a password on the server.
That's what anyone with half a brain should do if they're hosting v20- versions on the master server. As it has been made abundantly clear, it's impossible for the master server to really tell what version you're using. So if you just set a damn password, random kids won't stumble into your server and have their Blockland crash and you won't ever be found out. Even if you were found out, I doubt Badspot would even care because the server is passworded, he has no reason to care unless you start tricking people into joining to forget with them.