Blizzard lays the law again:
It has come to our attention that certain individuals are selling Blizzard's in-game property for cash on auction sites such as eBay and on personal websites. The World of Warcraft Terms of Use clearly state that all of the content in World of Warcraft is the property of Blizzard, and Blizzard does not allow "in game" items to be sold for real money. Accordingly, Blizzard Entertainment will take any and all actions necessary to stop this behavior. Not only do we believe that it is illegal, but it also has the potential to damage the game economy and overall experience for the many thousands of others who play World of Warcraft for fun. In order to promote a fun and fair environment for all our customers, we are actively investigating those individuals who engage in this inappropriate activity and reserve the right to take legal action against these individuals to protect World of Warcraft for all those who "play by the rules." If you are found to be selling in-game property (such as coins, items, or characters), for real money, you will lose your characters and accounts, and Blizzard Entertainment reserves its right to pursue legal action against you as well.
We also want to remind potential buyers in the game to please refrain from buying in-game property with real money. We understand the temptation to purchase better items, but Blizzard, and not the seller, does own all in-game property. In addition, we feel that characters can find ample equipment and money within the game through their own adventuring and questing. Please understand that if you do purchase in-game property from sellers on eBay and personal sites, we may temporarily suspend your account, and at the very least, delete the offending items.
Thank you for understanding our position. Blizzard Entertainment is committed to maintaining the atmosphere of fair play and fun in World of Warcraft.