Air Passenger Fairness Act of 2012 - Prohibits an air carrier or airport operator from establishing an expedited line for a specific category of passengers to be screened at an airport checkpoint before entering the airport's sterile area. Exempts from the prohibition the establishment or operation of an expedited: (1) airport screening checkpoint line for disabled passengers; or (2) security screening program by the Transportation Security Administration (TSA) of the Department of Homeland Security (DHS) or any other federal, state, or local government agency.