Comment by Borealid

No, looking up your face in a list of faces is searching FOR you, not searching you.

Searching you means taking an inventory of the items on your person. It does not mean looking at you. In some cases, imaging you can be a "search" even where there is no physical contact (for example: a millimeter-wave scanner), but a photograph in a public place has never qualified as a "search" in the USA.

I understand your feelings, but so far as I know things like gait recognition, facial recognition, or even an iris scan derived from an ordinary photograph have never qualified as a "search" under U.S. law. Feel free to correct me if I am wrong on this: it's quite difficult to prove something has _not_ happened.

I think the legal line is not when it "becomes biometrics" or becomes identification. The legal line is when you are revealing a private property about an individual (for example, their blood type, or the contents of their pockets). Nothing visible to the naked eye in public is considered private, so nothing that derives identity from that public information is a "search".

As a nice easy example... an officer smelling alchohol on the breath of a person in the course of a conversation is not a "search". An officer compelling that same person to breathe into a breathalyzer machine is. Applying the same standard to faces, you cannot make an individual put their eye to a scanner without reasonable suspicion, but if you can get a biometric scan from the invidual as they happen to walk about their day, doing that isn't searching them...