[dogma1138]

You don't need all photos, you can run a basic face recognition algorithm like the ones used in cameras to identify good candidates and just filter all other photos.

Profile photos are good enough, and with the amount of selfies people are taking there should be more than enough candidates for a full facial recognition matching.

Also facebook isn't the only social network, LinkedIn profile pictures are usually much better for facial recognition Google+ profile pictures are also usually quite good because they crop your face into that silly circle.

[spike021]

Oh I see. thanks for the explanation. LinkedIn definitely makes more sense too since more users will have clearer profile shots.