For some 15 years, airport security has become steadily more invasive. There are ever more checkpoints, ever more requests for documents as you make your way from the airport entrance to the airplane. Passengers adapt to the new changes as they come. But my latest flight to Mexico, originating in Atlanta, presented all passengers with something I had never seen before.
https://fee.org/articles/welcome-aboard-but-first-us-marshals-will-scan-your-retina/