I remember a charming game we used to play called Nazi, where one kid would ask another “Vhere iz yor paperz pleez?” No matter what the victim’s answer, he would get smacked in response. We thought it was hilarious.

Customs and Border Patrol seems to use the same approach, but they’re playing for real. See, for example, Homeland Security Detained US Citizen Inside The US, Used Intercepted Emails To Quiz Her About Her Sex Life

Also see the website of the Identity Project: Papers, Please!.