It makes me wonder what legal consequences it's gonna have once this kind of technology is widespread among all smartphones with high identification reliability? What's to stop anybody from combining different biometric identification systems into one device? A combination of Touch ID/Face ID, coupled with some voice recognition and whatever else is possible with biometrics, would probably be able to identify the user with a very high certainty.
Smartphones are also increasingly being turned into an "ID card replacement", even banks have been pushing to use them as a replacement for CC/Debit cards for years.
Which kinda makes sense considering how not every country has ID cards but a vast number of people on this planet have smartphones or at least mobile phones.
If one wanted to index the whole human population of planet Earth, it would probably a good start to "just" collect the SIM/IMEI data from all mobile phones in circulation. 
It's still a quite dystopian idea of a future, where the identity of a person is solely defined and legitimized by their smartphone/mobile device. Scary thing being: We are closer to this kind of future than it might seem; the aptly named US program "Skynet" uses mobile metadata for targeting selection of drone strikes, has been doing so for quite a while 
Does every design meeting at Apple start with: "What beloved feature can we remove and replace with something no one fucking cares about?"
(I say "defeat". Schiller just said the chances of a false positive were higher with twins than the 1/1,000,000 base rate [compared with his claim of 1/50,000 for TouchID])
It's 1/1M for strangers. Is it 1/10k for family members? 1/100 for close look-alikes?
The difference between FaceID and TouchID is that you don't have pictures of millions of people's fingerprints available publicly online...
I've worked on a few facial biometric systems in the past and the false positives were really shocking about 65% of them were cross sex and virtually none of them looked alike.
People tend to look at different flesh centric facial features and things like hair style, eye color and overall superficial appearance is what we see.
Biometrics see distance between various points like eyes, nose bridge cheek bones etc we tend to actually overlook those fine features when it comes to doppelgängers.
From friends that still work in the field gate analysis seems to have the lowest rate of false positives yet so maybe IPhone X2 will require you to dance to unlock.
Please sneeze to unlock phone
Or do they actually have enough differences that the phone can pick up on, even if people can't tell them apart?
I've only known one set of identical twins, back in high school, and at first I thought they looked the same. After a while, however, you can recognize the differences. I suspect a phone has enough data points that it sees them as different people.
China, Japan, S.E.A.: Surgical masks against smog, or to avoid spreading germs.
Northern Europe, Canada, Northern US: Winter clothing that covers the face to avoid the cold temperatures
Middle East: Religious clothing for women hiding their faces.
Anywhere with hot summers: Sunglasses covering the entire eyes, making it impossible to see if you’re looking at the screen (which is a requirement for FaceID unlock).
I am thinking that there will be the ability to program recognition with clothing that you own (color, texture) if you want to accept the risk. For most people I don't think they will be worried about something that has some of the same facial features stealing their phone. After all not everything will be blocked. And for that matter you can't do touch ID with gloves on, right?
> Middle East: Religious clothing for women hiding their faces.
Nothing to prevent a third party from offering a device which also allows touch id or simply using the alternate unlock. After all I don't think the amount of women hiding their faces in middle east countries means that the rest of us can't have this feature. How much business will they lose? In the end this is a business decision not a social one.
> Sunglasses covering the entire eyes, making it impossible to see if you’re looking at the screen (which is a requirement for FaceID unlock).
Once again will probably be able to allow use of sunglasses that you own with facial features that you have. Sure chance that someone could spoof you but for most of us not really a big threat. And someone needs the phone to do so and needs to know what you have programmed in as far as your clothing.
I wonder if the IR sensor can actually see through the sunglasses?
You've got to remember they sell nearly 50 million of these things every quarter. They don't just appear out of thin air.
Catch the perp, get full access to the device. -Apple