The Faces of Facebook is a website that has extracted 1.2 billion profile pictures allowing you to browse them. You can even find your own profile picture, it is ordered chronologically from the first profile to the last. You can see which one you are compared to the rest, when you created yours. Now think about how easy it would be for the NSA to find a person on Facebook, not through this website but through the fact that Facebook gives them access to all of this data already.
