My informant used to play World of Warcraft for a period of about 5 years, and during his time with the game, he has come across several stories.  The two stories he told me about were the SuperAIDS story and the Leeroy Jenkins story.  This story is about SuperAIDS.

According to my informant, SuperAIDS was the player given nickname of a debuff [essentially a curse] that a particular boss character would inflict upon the players.  This debuff would deal damage to the inflicted player and would spread to any nearby allied units.  The debuff could be cleansed by a particular class and be stopped.  However, this debuff would sometimes get on a player’s pet, and one of the ways to deal with this was simply dismiss the pet rather than wait for someone to cleanse it off, because it’s really hard to see if it’s on someone’s pet and just as hard to target the pet.  So players with pets would simply dismiss them and be done with it.  Unfortunately, the debuff didn’t go away, so when they went back to major cities, and summoned their pet, the debuff would still be there.  Once players figured out this was happening, they got their pets infected and brought them into the major cities and started spreading the disease intentionally.  The disease would spread rapidly between players and would kill almost anyone who wasn’t highest level.  Normally this would just be considered a prank but the disease would also spread to NPC’s [non-player characters].  The major problem with this was that NPC’s regenerate their health when out of combat and this regeneration outpaced the rate of damage from the disease.  So the disease would kill almost any player who came into contact with it, but it would never get off the NPC’s.  This is perhaps how the name SuperAIDS came about, because it didn’t go away.  Anyway, this meant that, as the disease was spread, more and more areas of the game became essentially uninhabitable because your character would just get infected and die over and over.  This persisted for about a week until the devs were able to patch the game, eliminating the disease from the NPC’s and preventing the disease from leaving the raid encounter.  And even though the game of WoW is played in several different servers, because the players all communicate online, nearly every server experienced this in some way.