Ugh. I turned it off.Introducing Face Recognition For More Features
Hi Weet, we’re always working to make Facebook better, so we're adding more ways to use face recognition besides just suggesting tags. For example, face recognition technology can do things like:
• Find photos you're in but haven't been tagged
• Help protect you from strangers using your photo
• Tell people with visual impairments who's in your photo or video
You control face recognition. This setting is on, but you can turn it off any time, which applies to features we may add later.
-The Facebook Team
But I bet they use it for a lot of things they're not mentioning in this friendly little blurb.