A tool that could track individuals and was under the perview of Executive Branch (eg Homeland Security) sounds pretty dangerous. Any political rivals of family members who go for STI screening, abortion clinics, gay bars, oncologist, or couples consoling could be either leveraged or leaked for political effect. Or you it could be used to track groups of people, activist, reporters. Or any number of ways I wouldn’t be able to think of.
What I was trying to say is that if you are trying to establish a totalitarism not having any checks and balances on something like that would be handly.
There are other, better, arguments in favor of personal liberty to use against facial recognition by law enforcement. Efficient, highly automated systems crush people who just happen to get caught up in them.
Technologies take time to develop and deploy, and the fact of their development and deployment is a red flag that tells you something bad is coming and gives you time to react before it can actually be put into place.
Setting everything up for turnkey totalitarianism is not wise.