I hardly think a face scan during a traffic stop counts as evidence that the infraction was committed. “Look here your honor, anyone with that face would have run a stop sign. No not the face they have, but this photo/3d scan I took!”

It's really a matter of creating a false positive to give the officer permission to search a car or a phone and find more incriminating evidence. End of story.

Laws regularly go obsolete because of new technologies. The issue isn't the letter of the law but the inflexibility in adjusting to new, more intrusive ways of invading privacy.

That law was written at a time where it was believed humans don't have databases in their heads. That is still true, but the effect can now be simulated with a mobile device, which brings new threats to agency as a free citizen of a nation.