Details of Second Lifes prison area for offending users are here.
Users who continue to offend are banned completely.
Its tempting to say that the dream of a new virtual utopia isnt viable, as we import the issues of the real world in to it. (Unlike heaven, which is by definition heavenly – depends what you mean by that, of course.)
But SL (etc) have one major sanction that real life doesnt have. Short of suicide, you have no real choice about being in reality. You have to exist somewhere, as someone.
You dont have to join SL or any other virtual world, or MMORPG: but if you do choose to be there, you have to accept that its your choice and that involves certain rules. Perhaps in a way this will bring back the concept of social responsibility which seems so lacking in real life?