[dspillett]

For privacy advocates the simple act of linking people that way is worrying enough. Not much of a concern for me (my government's creepiness is vastly overshadowed by its incompetence) but it could certainly be dangerous to free thinkers in certain regimes.

I find it hard to believe that they can't associate more information with those profiles than just who has who else as a contact (or has in the past), some derived/guessed and some from purchasing access to other data-sets, and I find impossible to believe that they won't if they can. Not just FB but other purveyors of advert targetting stalkerdom too. This isn't "don't trust the man" foil-hat paranoia - knowing as much as possible about as many people as possible is their well documented business model.