A virtual plague which began on September 13th 2005, the Corrupted Blood Plague was a glitch in World of Warcraft that killed lower levelled players. It began with the introduction of the new raid Zul'Gurub, which pitted players against Hakkar the Soulflayer, an end boss who drained hit points using a spell called Corrupted Blood. The spell was highly contagious, passing from player to player like a plague and causing vast amounts of damage to lower levelled players, killing them easily. Though the spell was designed to only function within Zul'Gurub itself, a glitch which allowed pets and minions to carry the plague beyond the confines of Zul'Gurub quickly caused a virtual epidemic, spreading the disease across the virtual world. The plague was so deadly that the programmers even had to impose quarantines to try and contain the spread, finally solving the issue a week later with a series of patches and resets. The whole thing was so unprecedented that it actually caught the attention of epidemiologists and counter-terrorist researchers who were interested in how players reacted to the virtual threat of the Corrupted Blood Plague. The whole thing may seem silly now, but ten years ago it was a pretty big deal; it caused a fair share of mayhem for Warcraft players, many of whom stopped playing the game entirely to avoid infection.
