Horde only
The chain quest 'Test of Lore' will later on give you a multiple-choice question as a quest. If you select the wrong answer, you will be given a buff "Mark of Shame". This buff will let you attack your Faction! If you kill civillians you will not be given DKs or reputation loss. The good part about this is that you can interrupt NPCs that your friends want to communicate to. If you die, you do lose the buff and have to answer the question wrong again (you can try to asnwer this as many times as you want). The wrong answers are the first 2, third one is the correct answer. If you accidentally answer it correct, dont worry! you still can attempt the wrong one.
Quest starts at Thousand Needles; http://thottbot.com/?qu=1149
Designated quest part(9); ttp://thottbot.com/?qu=6628
I have tried this on my server, I aggroed all the Auctioneers and told my guild to keep me healed. After 30 minutes, reapply with a mage at my side to lead me with portals. After a while of this non-stop, a GM msged me and told me 'not' to do it, but he did not force any actions upon me.