[adiabatichottub]

Or just runs out of batteries and you don't have a charging cable. Maybe you could ask a stranger for help, but you're in a country where most people don't speak your language. Or maybe people do speak your language, but you have a phone with a charging port that isn't standard in the country you're in. Also, you're about to miss your flight.

I think we can all agree that edge cases will always exist. The question is does this system make those cases better or worse. What's the backup in case the first-line system fails? You go talk to the airline agents and get a paper boarding pass printed?

The facial recognition system I'm much more wary of. Will it recognize you if you are coming back home with a black eye (happened to me one time)? Could your doppelganger cause confusion with the check-in system? Is this system significantly more convenient for the traveler that it's worth putting your biometric data into a database that could potentially be appropriated for other purposes?

[Freak_NL]

The language used here ('obsolete') strongly hints at making this the primary case, with any secondary option deemed inferior. It wouldn't surprise me if using a paper boarding pass will just flag you in the system for extra checks.

> Could your doppelganger cause confusion with the check-in system?

That's the scary one.

[devilbunny]

I’m a Global Entry member. I am already in all the databases ever, because I’m a doctor, so I just said f it and signed up. The facial recognition systems used by the US government- - if they get a well-posed picture of you (presumably with a lot of 3D detail) - are absolutely fantastic. I don’t even pull my passport out when returning to the US. I get a picture taken at a kiosk, I walk up to the line on the floor, and the agent says “you’re good, Devilbunny”. That’s it.