This feature was only rolled out in the US at first, and as of today, it has arrived in most of the world. While most Facebook features are opt-in by default, Facial recognition is an opt-out feature by default – meaning that you’ll have to go into Facebook settings to turn it off yourself manually if you don’t want Facebook to use its facial recognition technology on your photographs.
While it’s not a big deal for most people, it seems to have ruffled the feathers of some people. Anyway if you’d like to disable Facebook from automatically tagging you in photographs, head over to the privacy settings page, customize settings link, and under “things others share” you’ll find the “suggest photos of me to friends” option. Disable it and you’ll no longer be automatically suggested to be tagged in photographs – your friends will have to manually do it themselves.