Blizzard has released some more information on its labours to rid WOW of hacking and online gold:

In keeping with Blizzard's aggressive stance against cheating in World of Warcraft, we banned over 30,000 accounts in the month of May, and with that removed well over 30 million gold from the economy across all realms. The banned accounts were taking part in activities that violate the game's Terms of Use, including using third-party programs to farm gold and items, which severely impacts the economy of a realm and the overall game enjoyment for all players.

We will continue to aggressively monitor all World of Warcraft realms in order to protect the service and its players from the harmful effects of cheating. Please note that selling World of Warcraft content, such as gold, items, and characters, can result in a permanent ban of the involved accounts from World of Warcraft.

As tempting as it may be, try not to purchase online money, in the end, it just puts everything in the game out of balance (like 90 gold arcanite bars!).