Facebook told Wired that this new photo test was created to "help us catch suspicious activity at various points of interaction on the site, including creating an account, sending Friend requests, setting up ads payments, and creating or editing ads."
a friend sent me this: Facebook is now locking users out of account features, then demanding that those users "verify" their account to get back in by scanning an image of their face. AN IMAGE OF THEIR FACE. pic.twitter.com/T4TIsJFxX8— can Amy Goodman pls stop inviting Assange on thx (@flexlibris) November 28, 2017
Earlier in November, Facebook announced a trial for a "non-consensual intimate image pilot" program, where part of the process asked users to send such images to themselves on Facebook Messenger. This was intended to eventually prevent any of these images from being spread online by reviewing and hashing the image, "which creates a human-unreadable, numerical fingerprint of it." This way, if someone else did try to share the image on Facebook, the company's database of hashes would spot the image and prevent it from being uploaded.
As with any of Facebook's tests, it's unclear how widely available the new image verification system is currently, or if it will expand to a wider user base in the future. According to a deleted Tweet spotted by Wired, if Facebook asks you for the photo log-in you might be locked out of your account completely until you provide the image, with a message stating: "You Can't Log In Right Now. We'll get in touch with you after we've reviewed your photo. You'll now be logged out of Facebook as a security precaution."