Game creator Blizzard is investigating a large-scale hack that kills all World of Warcraft characters and NPIs, leaving entire virtual cities empty.
Speaking to the editor of WoW Insider, the BBC says hackers have created level one character that was able to kill every other gamer and computer-controlled character.
Level one priest wipes out all characters in the WoW city of Stormwind
Blizzard has told gaming sites that the in-game exploit has already been hotfixed and "should not be repeteable".
"It is safe to continue playing and adventuring in major cities, and elsewhere in Azeroth," a Blizzard representative says, amid appeals for more information.
World of Warcraft is a massively multiplayer online role-playing game that originated in 1994. With around ten million subscribed players, WoW is the largest game of its kind in the world.
New and old style online gaming is an enormous global business. Forecasts by Lazard Capital Markets analysts put WoW revenue at US$1.6 billion (A$1.57 billion) annually in 2010, with the total games market at around US$20 billion (A$19.58 billion).