Because of this, players that were legitimately called out by the community soon found themselves with nothing to do, because nobody would group with them. Their only choice was to re-roll on another server and start over -- at this point, you couldn't even transfer your characters to other servers if you wanted to. And oddly enough, the system that wasn't really a system completely worked. Players that were jerks eventually had their jerk-ish ways come back to bite them on the butt, and the rest of the server community happily resumed playing.
While cross-realm play is incredibly useful for opening up the player base, it's had the unfortunate side effect of getting rid of that accountability aspect of the game from vanilla. What's to be done about a jerk if that jerk is on another server?
Stubborn brought up an interesting point in all of this. It can be likened to the relationship between bully, audience, victim and authority. A bully hounds a victim for the audience -- for attention, for support, for popularity -- and the victim goes to the authority for help. Theoretically, the authority should come down on the bully for what they are doing. In Blizzard's setup, we never see that relationship between authority and bully. We never know what's being done in these cases, or even that anything is being done at all. Which leaves the victim feeling powerless and disillusioned; the worst possible place to be.
Yet in vanilla, this little power struggle played out very differently, and it was for one very specific reason. The audience, in the form of the server community, had their own say in the matter. While the audience was not the authority, they could still choose who to support, and who to punish in the form of denying groups, chatter, and all that cool stuff that comes with playing an MMO. Because of this, bad behavior was by and large kept in check. So the question is, can anything be done about this now, in an age of cross-server everything?
The results have been huge. 50% of the players warned by the Tribunal just once never end up there again. 94% of the players who get enough reports to warrant facing the Tribunal are punished -- by their peers. It's taking the accountability for being a decent human being and putting it back where it should be, in the hands of those that have to deal with these problematic players on a daily basis.
Is this something that would work for World of Warcraft? That's a good question, but I think it's already been answered to a degree. It was answered back in the days before cross-realm groups, dungeons and raids, when server communities performed the task of policing problem players all on their own, without the input of authority at all. Take a look at Stubborn's full post for more -- and for more on League of Legend's unique Tribunal system, the League of Legends wiki can fill you in.