<<I thought that part of the reason for fingerprinting / pictures was that it would be required unless your passport was machine readable.>> Nope, that was the Transit without Visa program that allows just what it implies. If they can scan it, you don't need a visa to hang out in the already sterile zone of the airport until your flight leaves. That was really stupid. This is for all people entering on some sort of visa, whether tourist, work, student or otherwise.