Two things.
1. I think Tom has it right - we can rely on people reporting the type of behavior we are looking to discourage rather than going out and conducting witch hunts to look for it.
2. In the past I have been against attempting to criminalize 'clanning', if only because it is extremely difficult to define what exactly that term means in such a way that you can pass judgment. As Katyanna and GoldPanda have alluded to, many players have forged OOC connections with other players that they met through the game and many other players play with RL friends and family including myself, but most such players do not engage in the kind of activity that is the focus of this discussion.
I still have concerns about this. I think if we do add something like this to the social contract, the cases we get are going to be extremely divisive. Competing isn't a crime. Where do we draw the line between playing well and power gaming? This is very much going to be a case by case thing. There's no way we're going to be able to establish sufficiently precise criteria in advance. "We'll know it when we see it" is going to be what it comes down to. Such lack of clarity can and will contribute to making these cases more divisive however.
