ACLU of Northern California: “While Congress has directed CBP to collect biometrics from noncitizens as part of the entry/exit program, Congress did not specify which biometric the agency should use, and from a privacy perspective, face recognition is (along with iris recognition) the most dangerous biometric to use. That’s because it has greater potential for expansion and misuse: for example, you can subject thousands of people an hour to face recognition when they’re walking down the sidewalk without their knowledge, let alone permission or participation. You can’t do that with fingerprints. Face recognition databases could be plugged in to every surveillance camera in America, creating a giant infrastructure for government tracking and control. Wagner told me that the agency opted for face recognition instead of fingerprints because of the greater ease and practicality of the technology as well as the “optics of us taking fingerprints from people.” Of course, fingerprints do have a negative association in the public mind—but that’s because of their use in tracking and identifying accused criminals. And tracking and identifying is exactlywhat the photos are being used for here. If, as Wagner suggests, taking a photo seems more benign to the public, that’s only because the public’s intuitions about privacy have not caught up with what the technology can do. And fingerprints work fine in the context of international travel, as they are already used for the Global Entry frequent traveler program.”