Yes I do!

They are working towards requiring it for all travelers.

Why: Think of this as a trial working towards full automation. They aren’t there yet and are not probably legally allowed to do so, but the idea is that you can be fully tracked like the British, Chinese, and other biometric adopted countries.

Prevention: Reliability and legality. As I mentioned I don’t think they can force it in the US for travel yet as it’s not legally allowed, nor is biometrics entirely reliable as is apparent when facial recognition fails.

They should have said, but I guessing they didn’t because it’s easy and indicates it at the checkpoint. You tell the agent you are declining the biometric identification. Do it as soon as you hand the agent your ID, don’t step in front of the machine, then follow instruction (probably step alongside so they have a clear view of your face).