I'm not sure how is it for the admins but for the VIPs there are absolutely no trouble banning a player who is name changing.
Guys, I actually saw such thing happened in Stronghold today. A hacker came in to the server and his name is vary (somehow mimic in-game people's name).
The point is, I did not manage to screenshot and record him.
Next time type "record" <any demo name here> without the (") in your console and you'll be able to record anything.
Oh and after you're done recording type "stop" in your console without the (").