From Seed, a paper entitled 'Social Networks are like the Eye', that discusses how a variety of 'tastes' can flow through a social network - including privacy.
In one project developed from this research, we considered whether someone wants to keep his or her information private on the Internet. Initially, without trivializing this serious topic, the issue of privacy was a methodological nuisance. But then we realized that, in addition to its conceptual importance, we could treat privacy as a taste. And we saw that the taste for privacy flowed through the network so that if I adopt privacy settings on Facebook, the people to whom I am connected will be more likely to adopt privacy settings.
There's the rub. It's in my interest to keep my privacy settings high (all else being equal, which it isn't). But it's also in my interest for others in my networks to keep their settings low (so I can enjoy the pics of them pretending to be a car in Munich etc).
However, given the great influence I have over my peers, my high settings will likely drive them to be more privacy protective as well - thereby limiting my fun.
It seems to me that my privacy settings, additional to the identity data they protect, are themselves PII, and that the view I choose to expose of those settings to the world should not necessarily map accurately into their real values. That way, I can protect my own privacy, without prompting my friends & colleagues to do the same for themselves.