I think it was UK Gatwick Airport, on the way to passport control. The passengers were shepherded into lines, and spaced at intervals above each line were ceili

I think it was UK Gatwick Airport, on the way to passport control. The passengers were shepherded into lines, and spaced at intervals above each line were ceiling-mounted cameras. Bright LEDs around the camera lens were flashing in rotational patterns - designed to instinctively draw attention, and hence make facial recognition easier.