Wanted to make a quick thread about this since I just encountered it. I like that we don't have to use RSC and choose our own names but this comes with a few problems too, e.g. same names, people may not know who is who, and if 1 of the people starts to impersonate the other, then we've got a problem. And this is really easy to do, just go to the settings, change your name and done. /register and /login would probably fix these, but not every server may have it.
I say all this because I saw someone using the same name as me in-game, except with lowercase letters.
No offense to the person if he also had this same name before though, just wanted to point it out.