Not quite sure I agree with that. I think the argument is that Facebook has pictures of me as long as any one of my friends has a picture of me, and has posted it on their own Facebook.

Similar to the problem with Google having access to a large percentage of emails, Facebook will have pictures of me regardless of whether I choose to personally have a Facebook account or not. Assuming that I do have a Facebook, with a network of friends, they can also tag me in their pictures (and therefore available to Facebook) even if my own privacy settings are turned all the way up.