Heres the skinny: Blizzard adds in a new instance, Zul'Gurub. Inside is the god of blood, Hakkar. Well, when you fight him he has a debuff called Corrputed Blood. It does like 250-350 damage to palyers and affects nearby players. The amazing thing is SOME PLAYERS have brought this disease (and it is a disease) back to the towns, outside of the instance. It starts spreading amongst the genral population including npcs, who can out generate the damage. Some servers have gotten so bad that you can't go into the major cities without getting the plague (and anyone less than like level 50 nearly immediately die). GM's even tried quarantining players in certain areas, but the players kept escaping the quarantine and infecting other players.via Boris Via Wonderland
Then, I ask Jonas about this and:
It was a sight to behold. Some tell me, IF was finally usable and that the lag was gone for once, but Orgrimmar was fun nevertheless. Red blobs splashing everywhere, healing and renew/regrowth was being mass-spammed, and there were more bodies and skeletons around than I've ever seen, and I've raided IF before.
My biggest fun was screwing with those incompetent GMs. Some used their own chars to herd us, which made the plague transfer even faster, others messaged and threatened consequences if we did certain things. The idea was, to move all infected players into instances, where we could be by ourselves, so we hooked up into large raid groups, rezzed instead of corpse walked, and re-infected ourselves before hearthstoning back into Org. Bog Troopers, a huge horde guild in Org, raided Stormwind, which was almost empty, and killed the child king (no HK, there, you have to kill the Guardian) before walking into the Stockades, farming gold. The GMs congregated up on Honor's Stand, so we had a handful of players up there, stealthed, and infecting them. It was more fun than any other world event EVAR!.
Not much to add. Just hilarious.