Face id is putting a very good camera very close to your face and asking it if the face inches from the screen and stationary with respect to the camera matches exactly one face.

Facial recognition is asking a worse camera if a moving partially obscured face is one of 338M legal residents and citizens or potentially millions of illegal folks. Since this is inherently an incredibly harder task it doesn't take much to make it impossible.

Agreed that there's no perfect solution.

But one can, and should, make it harder, and if your head, eyes, and face are covered (which is exceedingly easy and inexpensive to do with a ball cap, sunglasses, and a face mask) it's going to beat all but the best systems.

Thanks. I think that's enough to see where you're going. It's on me to find better evidence, so I looked and it looks like a 2020 NIST report suggests masks increase the failure rate in 89 tested algorithms from 0.3% to 5-50%.

https://www.nist.gov/news-events/news/2020/07/nist-launches-studies-masks-effect-face-recognition-software

That failure rate is enough to give plausible deniability and reasonable doubt in a court, I'd wager. But I'm sure ICE sees a higher failure rate a feature since it likely gives them more pretexts to arrest. At least we know the technology isn't reliable enough to support it.