A Pomona College student who says he was detained at a Philadelphia airport because he was carrying English-Arabic flashcards filed a federal lawsuit Wednesday against employees of the Transportation Security Administration, the FBI and the Philadelphia Police Department, according to the American Civil Liberties Union.

Nicholas George, a senior majoring in physics and Middle Eastern studies, was returning to California from Philadelphia in August when he was randomly selected for extra screening at Philadelphia International Airport, the lawsuit filed in U.S. District Court in Philadelphia states.

When George emptied his pockets, he took out the flashcards.

Authorities detained him in the screening area for 30 minutes before he was questioned by a TSA supervisor, the lawsuit states. At one point, the supervisor asked George if he knew who committed the 9/11 terrorist attacks, according to the lawsuit.

George answered, "Osama bin Laden."

"Do you know what language he spoke?" the supervisor asked, according to the document.

"Arabic," George answered.