Update, 10/29: Bumped up. Be sure to read the very interesting conversation in Comments it's inspired!

Senban Babii has some thoughtful thoughts about Second Life social drama, relating them to "the magic circle", a concept first described by historian Johan Huizinga. In a virtual world like Second Life or an online game like Modern Warfare 2, different standards of morality apply. With Modern Warfare, as Senban notes, suicide bombing is actually rewarded, whereas in the real world, it's generally considered horrific. So with SL:

[W]hen those residents playing in Second Life attempt to force other residents to conform to certain moral values and expressions, they are actually showing themselves to be unaware of the fact that not only is the Second Life playspace different to the outside world, it also contains an asymmetric morality and that if they are not prepared for this simple realisation, then perhaps they should not step inside.

This is roughly true, but I think the sociology of SL is even more complex: In Second Life, there are multiple, overlapping magic circles, which often have conflicting rules. Here's why: