Facebook - the black hole
It wants your data, all of it.
Even if you’re not a Facebook user, chances are that your computer is carrying cookies from The Social Network™. They’re scattered all over the Web like digital malarial mosquitoes waiting for the next host. They’re also, according to Austrian law student Max Schrems, part of an infrastructure that allows Facebook to build “ …
I've always thought social networking sites were questionable in DP law anyway.
If I choose to keep information on my friends on my PC that's fine (I'm talking contact details, etc.) because it's for personal use and that's allowed under DP law. If however I stick any of that info on a social networking site then I'm into a DP grey area. Just so long as I don't publish that information for others to see then I'm still OK, if I do allow anybody else to see it then I'm not. Where it gets grey however is when we consider whether or not the operators of the social network in question have access to that data. If they access that data then they are breaching DP law. If they actually do anything with that data then they are really breaking the law.
If they are using the data to build "shadow" profiles of my contacts then I wouldn't be at all surprised. Which is one of the many reasons I don't have and account on any social network.