Facebook has introduced tag suggestions which is aimed at making it easier to tag (assign names) to multiple pictures on the social networking site. Tag suggestions uses facial recognition software to make the suggestions
FROM THE BLOG
Because photos are such an important part of Facebook, we want to be sure you know exactly how tag suggestions work: When you or a friend upload new photos, we use face recognition software—similar to that found in many photo editing tools—to match your new photos to other photos you’re tagged in. We group similar photos together and, whenever possible, suggest the name of the friend in the photos.
If for any reason you don’t want your name to be suggested, you will be able to disable suggested tags in your Privacy Settings. Just click “Customize Settings” and “Suggest photos of me to friends.” Your name will no longer be suggested in photo tags, though friends can still tag you manually. You can learn more about this feature in our Help Center.