In Australia retailers might get penalty if they sell World of Warcraft or other massively multiplayer online games due to the New South Wales Classification Enforcement Act which prohibites publishers and retailers from selling unclassified computer games. Anyone crossing the line will be fined hard ($1100 to $11,000), even a 12 months' imprisonment.

The games industry believes online games are legal for sale without having a single player component from classification requirements, however, according to Robert McClelland, the spokeswoman for Federal Attorney-General, "The National Classification Scheme does not distinguish between games based on whether or not they contain a single player component."

Not just World of Warcraft, Age of Conan, Warhammer Online and Pirates of the Burning Sea are all sold without classification

For more information, here is the original article link:
No classification: online games legal minefield