This really just sounds like Dual Boxing, with some rather...interesting people.

If it really bothered you, why didn't you just leave instead? Like, let's be honest here, if something this small bothers you, then uh...you should grow some thicker skin.
I encountered worse, I either just ignored them or left. Simple as that.

EDIT: I hope you know the current FFXIV client allows 2 ffxiv.exe's. So, yeah. Probably another dual boxer.

sneep.