Almost five years ago, I wrote an article titled The 10 people you need to know in WoW. For some reason it never occurred to me to write a counterpart on the people you need to avoid. While I think these unpleasant folks are less important and influential than the people you actually want to have around, there's no denying that, once present, they can do a lot of damage to your ingame experience.
If you haven't had at least one supremely frustrating experience yet as a result of the douche-nugget brigade, you are fortunate indeed. For the rest of us, some of the following players will be all too familiar.