Apple says Face ID on iPhone X might not be as secure if you're under 13 or a twin
https://www.cnbc.com/2017/09/28/apple-iphone-x-face-id-not-as-secure-under-13-or-twin.html
If you're under 13 or have a twin, it might not be a good idea to use the Face ID unlocking system on Apple's new iPhone X.
The U.S. technology giant released security guidelines on Wednesday about Face ID – the iPhone X feature that allows users to unlock the device just by looking at it. In the document, Apple said that the probability of a random person unlocking an iPhone X with Face ID is 1 in 1,000,000 versus 1 in 50,000 for its previous fingerprint sensor.