Face recognition technology has been around for years. A partner and I even implemented a rudimentary tool for it in a few weeks in an AI course. I always wondered why Facebook couldn't take advantage of this and save the world thousands, if not millions of cumulative hours tagging photos.
Tagging friends in a photo is a meaningful social action, just like commenting or liking a status update. Automating this would give users one less way to interact with their friends on the site.
Even a 5% error rate is unacceptable. People may take offense to machine tag errors.
Second, facebook probably likes the time commitment people make to tagging photos and adding friends in order to tag them to the picture. It increases communication and also adds cases where people get facebook invites so they can get tagged.
The solution to the 5% error is to do the tagging automatically, but make the uploading friend confirm each photo to ensure that it was tagged properly.
I don't consider tagging itself to be inherently social. Being in a social setting with someone is what was social. Putting a picture of someone on Facebook is social. You can still comment on an auto-tagged picture just the same as a manually-tagged one. The only difference is that you save some time for those people who contribute the most (the friends who take dozens of pictures at every event and then spend a couple hours uploading/tagging them the next day). By decreasing the necessary effort of photo-sharing, I would expect to see more uploading and tagging.
A side benefit is that it could eventually make discovery easier. How many pictures do you have at a bar or somewhere else with a bunch of people you don't know in the background? How many times have you hung out someone somewhere, have a picture of them, but didn't get or can't remember their name? Automatic recognition gives you a better chance of meeting some of these people again.
For those saying this is a privacy issue, the uploader doesn't have to see the auto-tag of a non-friend. Instead, the person who has been auto-tagged could be notified and have the option of allowing/disallowing the tag to occur.
I read facebook looked at doing this, but their users were already manually tagging all their photos (and cool with that) so the additional hardware/implementation resources were errrr spent elsewhere.
there are a lot of situations where you don't want to tag a photo of a friend, the way tags are implemented on facebook.
i generally wouldn't tag a friend in a picture where they look bad, and there are all kinds of social situations where a friend wouldn't want to be tagged in a particular photo -- because one girl would see them with another girl, for example.
