You all know it, not going into details, go to Guo-lai halls and see for yourself. Theres people doing it every minute. I know it's been around for a long time and theres very little blizzard has done to fix it.
My question is though, should it be bannable?
My personal answer, yes it should, your gaining access to areas which you shouldn't normally have, and especially with guo-lai halls with chests behind them awarding gold and rep.