An unknown man passed through a TSA checkpoint in Philadelphia and flew to Chicago using a boarding pass that belonged to another person on Sunday.

TSA only realized the mistake when Brad Gertz attempted to check in to his flight to Chicago. And was told his boarding pass was given to another person.

"You would think that the person who checks the ID with a ticket would look at the name...not just the destination," Gertz said. "The fact that someone got through security as me is completely unacceptable."