Super Bowl 2001 fans were secretly treated to a mass, biometric scan in which video cameras tied to a temporary law-enforcement command centre digitised their faces and compared them against photographic lists of known malefactors. Everyone entering Raymond James Stadium in Tampa, Florida last Sunday was subjected to the surveillance system cameras, set up at the entrance turnstiles. No notice or disclosure was ever given, and no one, therefore, had an opportunity to decline to enter the stadium if they should have objected to this unprecedented treatment.
Awesome! No need to get consent! And this was pre-9/11.