This is a nice example of the kind of thing that bothers me. I don't have a smartphone, my address book is mine. But given that probably 99.9% of all my contacts do have a smartphone with Android on it or a Facebook account there is a fair chance that my address book can be reconstructed from theirs. So I can't even opt out, no matter how much I would like to, my 'spot' in the social graph is defined anyway.