Facebook has announced that it is rolling out a new feature which leverages its facial recognition technology to tell you when it thinks you’ve appeared in a photo but haven’t been tagged.

The company says that this will give users more control over how their images are being used on its service by letting them know when they have appeared in a picture on its site and then giving the options to tag themselves, leave themselves untagged, or to reach out to the person who uploaded the picture if concerned.

According to the official blog, Facebook says: “We want people to feel confident when they post pictures of themselves on Facebook so we’ll soon begin using face recognition technology to let people know when someone else uploads a photo of them as their profile picture. We’re doing this to prevent people from impersonating others on Facebook.”

Here’s how Facebook describes that technology at a high level:

“Our technology analyzes the pixels in photos you’re already tagged in and generates a string of numbers we call a template. When photos and videos are uploaded to our systems, we compare those images to the template.”

Facebook says the feature is rolling out now, except in Canada and the EU.