I don't think it's very true at all. From what I've read, PhotoDNA is used to detect child pornography by comparing a photograph's "hash" against a database of

I don't think it's very true at all. From what I've read, PhotoDNA is used to detect child pornography by comparing a photograph's "hash" against a database of hashes for known pornographic images. There's no facial recognition involved. More here: http://news.ycombinator.com/item?id=2564235 http://news.ycombinator.com/item?id=2564235