Facebook got into a lot of trouble the first time it did this
Facial recognition has proven a tricky thing for Facebook. People have an unnatural fear of it even if there's nothing inherently evil or all that different about it. Yet plenty of people and privacy groups complained about it so Facebook backtracked on the feature and disabled it last year.Not for long though, photo tag suggestions are now enabled again on Facebook. Basically, Facebook will uses photo recognition to figure out which of your friends are in a photo and then suggest their names if you want to tag them.
It makes photo tagging easier and faster. It also only works on friends and there's no inherent privacy issue since all it does is help users realize something they already know. It doesn't reveal the identity of anyone you're not already friends with.
Still, Facebook is not making too much of a fuss about it, in a simple post on its privacy page it announced that the feature is working again in the US.
"We're re-enabling the feature in the United States so that people can use facial recognition to help them easily identify a friend in a photo and share that content with them. This is the same feature that millions of people previously used to help them quickly share billions of photos with friends and family," Facebook explained.