Facebook is currently testing out a feature that works very similarly to Apple's Face ID technology in the upcoming iPhone X. For when you get logged out of your account, Facebook is testing a way for you to regain access using a photo of your face, especially useful for when you're unable to use two-factor authentication.
When TechCrunch asked Facebook about the new feature, they had this to say:
“We are testing a new feature for people who want to quickly and easily verify account ownership during the account recovery process. This optional feature is available only on devices you’ve already used to log in. It is another step, alongside two-factor authentication via SMS, that were taking to make sure account owners can confirm their identity.”
Looks like Apple may have really started something here.