Plague epidemic speeds across Azeroth
Gamers aren't known for their steadfast refusal to make use of any bugs or exploits present in a given system. While exploits are normally made to gain material or martial advantage over other players, sometimes it's just because being a scallywag is fun. Seven years ago we saw what was perhaps the most wide-scale example of such an exploit, as Warlocks and Hunters used their pets to spread a Corrupted Blood epidemic through World of Warcraft. Yesterday, a similar opportunity reared its disease-riddled head: A patch allowed Death Knights to use their plague skills on friendly players.
While the Corrupted Blood epidemic is somewhat celebrated in WoW, devs apparently weren't willing to have a repeat. A fix came out in the wee hours of the morning to keep Death Knights from wreaking too much havoc.
[Thanks to alert gamer Collin for the tip!]
