An anonymous reader writes "The Harvard Law Review, a journal for legal scholarship, recently published a short piece on the privacy implications of online photo-tagging (pdf). The anonymously penned piece dourly concludes that 'privacy law, in its current form, is of no help to those unwillingly tagged.' Focusing on the privacy threat from newly emergent automatic facial recognition search engines', like Polar Rose but not Flickr or Facebook, the article states that 'for several reasons, existing privacy law is simply ill-suited for this new invasion.' The article suggests that Congress create a photo-tagging opt-out system, similar to what they did with telemarketing calls and the Do-Not-Call Registry." How would you enforce such a registry, though?