Face ID on Apple's iPhone X will be limited to one person per device
The Face ID system on Apple's iPhone X will only recognize one face per device, short-circuiting a strategy some people used with Touch ID, according to Apple.

The limitation was confirmed by iMore's Rene Ritchie, as well as by TechCrunch. The measure will force iPhone X owners sharing with family to either unlock the device themselves, or make sure relatives have their passcode.
Touch ID lets people add multiple fingerprints through the iOS Settings app. Ostensibly for this is for one person using multiple digits, but in practice, it's possible to reserve a few for loved ones -- ensuring for example that a phone's data isn't inaccessible in an emergency.
iOS doesn't normally support multiple accounts, and the Face ID setup process scans users at a variety of angles, in theory elimnating any need to save several faces. The technology should even adapt as a person ages, changes hairstyles, or adds accessories like hats and glasses.
Face ID has already proven controversial for other reasons, such as concerns about security and privacy. U.S. Senator Al Franken has submitted a letter to Apple CEO Tim Cook, asking him to provide details on how the company intends to protect customer data, prevent spoofing, and support a diverse range of people.
It's uncertain how a single-user limit will affect other aspects of the iPhone X, such as its ability to stay unlocked when it senses a person looking at it. If that's cued to a single individual, a device might suddenly shut off when it's being shared with a friend.
The iPhone X with the Super Retina Display and FaceID ships on Nov. 3.

The limitation was confirmed by iMore's Rene Ritchie, as well as by TechCrunch. The measure will force iPhone X owners sharing with family to either unlock the device themselves, or make sure relatives have their passcode.
Touch ID lets people add multiple fingerprints through the iOS Settings app. Ostensibly for this is for one person using multiple digits, but in practice, it's possible to reserve a few for loved ones -- ensuring for example that a phone's data isn't inaccessible in an emergency.
iOS doesn't normally support multiple accounts, and the Face ID setup process scans users at a variety of angles, in theory elimnating any need to save several faces. The technology should even adapt as a person ages, changes hairstyles, or adds accessories like hats and glasses.
Face ID has already proven controversial for other reasons, such as concerns about security and privacy. U.S. Senator Al Franken has submitted a letter to Apple CEO Tim Cook, asking him to provide details on how the company intends to protect customer data, prevent spoofing, and support a diverse range of people.
It's uncertain how a single-user limit will affect other aspects of the iPhone X, such as its ability to stay unlocked when it senses a person looking at it. If that's cued to a single individual, a device might suddenly shut off when it's being shared with a friend.
The iPhone X with the Super Retina Display and FaceID ships on Nov. 3.
Comments
And so much of this article is just ridiculous, like this:
Face ID has already proven controversial for other reasons, such as concerns about security and privacy.
Only by people who don't understand how it works.
and this:
a device might suddenly shut off when it's being shared with a friend
Give Apple some credit here.
Here's the thing: with the device ogling its user, it will know not to 'suddenly shut off' because it knows you're looking at it.
Yeah I dunno what’s up with Roger’s comtiunued suggestions of security and privacy concerns. FUD: it’s what’s for dinner.
As to the privacy concerns, they were raised before with Touch ID. I don't see how this is any different. If anything, it's less of a concern, since your face is readily visible in public at all times whereas your fingerprints are somewhat more 'concealed.' Either way, from their description, the security seems to be similar if not the same for both systems, so I'm not too concerned. Besides, you don't have to use either system if you're really worried.
The use case is just different: "Honey, can I borrow your phone? "Sure." "Thanks, look over here." Now it supports remote handsfree (no touching required) authentication, within a foot or few anyway. I can see this being fairly useful in various circumstances.
EDIT: On on more thoughtful reflection (?? LOL) it doesn't matter. Slide-to-unlock. Doh!
https://www.franken.senate.gov/?p=press_release&id=2815
Needless fearmongering aside, no one should take any company (even Apple) at their word, especially not a U.S. senator. I would not be surprised if, after Apple responds to Franken, the senator is then praising Apple for its industry leading focus on privacy and security.