At TSA checkpoints at the airport, you have to actively ask to opt-out.
I'm always worried that actively opting-out puts you on a government list and there could be later, much larger ramifications, so I passively opt-in to blend in with the masses.
unless of course, you are willing to take ownership and accountability of my data and promise me minimum of $100k in compensation for data breaches and leaks indefinitely from your storage of my face. You can figure out how to pay for insurance to pay for this.
/oh you're not interested in even talking about this? Sounds like you have something to hide. (this fun conversation would not be well perceived when you that you ask for accountability for their actions and propose a solution. making a contract for this surely can't be super hard, but getting them to sign it and be accountable to it would be blocked hard)
So face is just on factor: now they look at gait, and other body parts that can serve for identification.
I enjoyed that. I will remember to opt out again.