Canada does this for passport control (as does the US in at least some circumstances - I know they did it every time I entered when I had my TN Visa, not sure i

Canada does this for passport control (as does the US in at least some circumstances - I know they did it every time I entered when I had my TN Visa, not sure if they do it for all foreign nationals or Americans). But this article isn't about passport control (which the TSA doesn't have jurisdiction over, it's handled by U.S. Customs and Border Protection); it's about passenger screening, presumably even for domestic flights.