A year or so ago, we were on a turn-around day in Port Everglades, and after doing the facial recognition machine, and as usual we were directed to sit in a group of chairs and wait for everyone to be processed.
At one point, a guy came marching into the area, ranting in a very loud voice that he objected, in the strongest of terms, to the government "taking his photo". His liberties were being abused.
Not sure if he was travelling without a passport, but I suspect that he had at least some other kind of photo ID, and that the US government already had on file his photo anyways.