You made me chuckle :)
First of all, I hope the child was wearing socks :)) So much for athlete's foot.
I thought of all the ramifications and creating an environment in which this intrusion would be possible, but decided to leave it simple. The emotional experience between mother and child. The loss of mother's control, her helplessness before the authority of the state. And the dramatic loss of the child's autonomy. And you're right, we do it now. Facial recognition, etc.
This was a great comment. Feel free to ruminate on any of my blogs.