@koyu Why ? That'd be awesome to use, the confusing question for beginners of multiple accounts on multiple instances (or the «which instance ?» problem) would simply cease to have a meaning. You wouldn't fear the incident taking your instance offline when you really needed to contact that person, you wouldn't fear anyone seizing the servers.

I'm not saying I want to think about how one would implement such a thing and still retain a tiny bit of privacy, just saying I'd find it way simpler and handy.