An Arabic language student was told he cannot sue two FBI agents and three TSA agents for a 2009 incident in which he was held at Philadelphia International Airport for carrying flashcards and a book which were critical of US policy in the Middle East.

Nicholas George was traveling from his home in suburban Philadelphia back to school at Pomona College in California in August 2009 when agents found flashcards containing translations for “bomb” and “terrorist” in his possession. He was then apprehended.

The college senior explained that he was in possession of the cards because they were study material. He had an interest in Middle East politics and intended to take a Foreign Service exam in the coming months.

“I want to serve my country using my Arabic language,” he told CNN after the incident. “And it seems crazy to me that for that I was arrested and treated like a criminal.”

He was kept for five hours; two of which were spent handcuffed at the airport police station. George, who was 22 at the time, was released after two agents from the FBI Joint Terrorism Task Force spent 30 minutes asking whether he was a member of a “pro-Islamic” or “communist” group. They also sought to determine whether he had met “anyone in his travels who was overtly against the US government.”

“They asked me why I had those words. I told them honestly because I had been trying to read Arabic news media, especially Al-Jazeera, and these are words that come up when you read the news about the Middle East,” George said.

George's lawsuit, filed by the American Civil Liberties Union (ACLU), asserted that the agents had violated his First and Fourth Amendment rights by violating his freedom of speech and conducting an illegal search and seizure.

Neither TSA nor the FBI disagreed with George's claims, including the assertion that agents scrubbed his cell phone for explosive residue and found no evidence.

A district judge disagreed with the agents' claim that they were immune from a lawsuit because they were trying to protect national security. However, a US Court of Appeals overturned that decision in a ruling issued Tuesday.

“It is simply not reasonable to require TSA officials to turn a blind eye to someone trying to board an airplane carrying Arabic-English flashcards with words such as 'bomb,' 'to kill,' etc.,” wrote Chief Judge Theodore McKee in the three-judge panel's decision. “Rather, basic common sense would allow those officials to take reasonable and minimally intrusive steps to inquire into the potential passenger's motivations.”

The court admitted that George had the right to carry the cards and deemed the arrest by TSA officials “at the outer boundary” of constitutional protection under the Fourth Amendment. The judges also said that “much of the concern had dissipated” when the agents found that George was unarmed. However, the search was still allowed to take place after that information was revealed.

“Suspicion remained, and that suspicion was objectively reasonable given the realities and perils of air passenger safety,” the ruling said, as quoted by the Associated Press. “In a world where air passenger safety must contend with such nuanced threats as attempts to convert underwear into bombs and shoes into incendiary devices, we think that the brief detention that followed the initial administrative search of George was reasonable.”

Ben Wizner, an attorney at the ACLU, told CNN that the government has consistently failed to explain why Arabic flashcards would rouse suspicion.

“Nick doesn't object and we don't object to the fact that he was searched closely, that his belongings were scrutinized,” Wizner said in 2010. “But once that's done, there's absolutely no justification for handcuffing him and locking him in a cell for several hours.”