In Response to this: http://www.efa.org.au/2009/06/29/will-second-life-be-banned-in-australia
What needs to be clarified is if something like Second Life is Refused Classification or Exempt from Classification. (or if its been looked at to be classified) I am unable to find this game on the Classifications Database. So it actually hasn't got a Classification and in that case based under the current classification laws it cannot be sold or hired in Australia. Since Second Life is free to play but you can upgrade your account for a fee to allow you to do more in the game, but the game itself is free.
"Computer games, whether they are locally made or come from overseas, have to be classified before they can be sold, hired, demonstrated or made available for play in Australia." source
I'm still not sure where this leaves Second Life.
There does not appear to be any Classification guidelines for Games where there is an online component and interactions with other players. So going by what Second Life is, walking around doing stuff? No violence? Is there anything sexual in the game, that the Devs put in? It'd fall under a rating less than M and could be Exempt from Classification. Also is Second Life classed as a game or a virtual experience?
Second Life has a business and Education part to it and so could be really be put under the Exempt from Classification based on the list here