Slate: Facebook’s Face-ID Database Could Be the Biggest in the World. Yes, It Should Worry Us. by April Glaser:
Every day, Facebook users upload hundreds of millions of photos to the social network. If they haven’t opted out, the software scans those photos in search of faces it recognizes. As users either agree or disagree with the recommendations of who should be tagged, Facebook’s algorithms get better. The company’s research suggests that Facebook holds ‘the largest facial dataset to date’—powered by DeepFace, Facebook’s deep-learning facial recognition system.