EIGHT YEARS after 9/11, we're used to changes in our routines. We show ID to get into office buildings, and take off our shoes at airports.

But should a college student flying back to school be handcuffed and held for five hours because he has Arabic flash cards in his backpack?

That's the way Nick George, a senior at Pomona College, in California, sees what happened to him at the Philadelphia airport two Saturdays ago.

George, of Wyncote, Montgomery County, was about to catch a Southwest flight back to school when stereo speakers in his backpack caught the eye of screeners at the metal detector.

When they looked though his bag, George said, they found his Arabic/English flash cards, and escorted him to a side screening area.

He figures it didn't help that his passport had stamps from Jordan, where he'd studied a semester, and Egypt and Sudan, where he'd gone backpacking.

And among his 200 flash cards were words like "terrorist" and "explosion." He was learning to translate the Arabic-language news network Al Jazeera.

"I understand I might warrant a second look," George told me. "They should have taken me aside, seen I had a legitimate explanation and a student ID and that I was carrying nothing illegal, and waved me on."

They didn't.

George said that Transportation Security Administration officers kept him in the screening area for what seemed like 45 minutes. Eventually a woman from the TSA arrived and began asking more questions, like how he felt about 9/11.

"Do you know who did 9/11?" he said that the woman asked.

George said that he told her that it was Osama bin Laden, and that she responded smugly, "Do you know what language Osama bin Laden spoke?"

Soon after that a Philadelphia police officer arrived and told George to put his hands behind his back. Without explanation, he slapped handcuffs on him and led him away.

George was taken to the airport police station, where he was locked in a holding cell with the cuffs still on. I guess that's what you do with a high-value physics major.

George said that he tried to be a model prisoner, and after about two hours a police supervisor removed the handcuffs. After a couple of more hours two FBI agents appeared and took him to another room for questioning.

They were polite, George said, and asked why he studied Arabic, why he'd been in the Middle East, whether anyone had ever asked him to join a terrorist group, whether he was "Islamic," whether he'd joined any Islamic or Communist (yes, Communist) groups on campus.

"They told me their job is more an art than a science," George said. "They come in and decide whether there's a legitimate threat, and in my case, they decided I was not a threat."

So, many hours after his backpack entered the metal detector, George was released with a ticket to fly the next day, but without an apology or explanation.

If there's one thing we know that the government needs in the post-9/11 era, it's more college students interested in learning Arabic.

George feels that he was treated like a criminal because somebody didn't like the flash cards. He wasn't injured or psychologically scarred, just ticked off.

"I didn't have a weapon or anything seditious, just words on paper," George said. "As an American citizen, I think I'm allowed to learn a foreign language and have flash cards."

TSA spokeswoman Ann Davis tracked down a report on George's encounter, and said that it wasn't the flash cards that got him flagged.

Davis said that George had been selected for screening before he even reached the metal detector by TSA behavioral-detection officers, personnel trained to screen passengers for "involuntary physical and physiological reactions that people exhibit in response to a fear of being discovered."

Davis said that the report indicates that in the screening area, George's "behavior escalated to a point where our officers deemed it necessary to contact the Philadelphia Police Department."

Davis couldn't say what behavior had caught the officers' eye or what escalating behavior he exhibited. She said the report did note that George had Arabic flash cards, but "that's not why we would call law enforcement."

The police story is a little different.

Lt. Louis Liberati said, just as Davis did, that TSA personnel initially selected George because of something in his behavior.

But Liberati said that it was the stuff that the TSA found in George's backpack and wallet that really aroused their suspicion: the Arabic flash cards with troubling words, a card that had George's name and Arabic script, and the longer hair in George's driver's license and passport photos than his current clean-cut appearance.

That's "an indicator sometimes that somebody may have gone through a radicalization," Liberati explained.

Liberati said nothing about "escalating behavior." Liberati said police checked with the FBI, and the feds decided that they wanted to come and interview George.

I reached George, now back in school, and told him the authorities' version of the events.

He said that it's "crazy" to think that he was acting suspiciously in line or that he had exhibited "escalating behavior" while being questioned.

He insists that he patiently explained everything, including the card with Arabic writing - his student ID from Jordan - which he keeps as a souvenir.

"I never raised my voice," George said, "but I did ask once or twice how much longer this was going to take because my flight was about to leave."

Liberati also said that he's certain that George had not been left handcuffed in his cell.

George is equally certain that he was. His wallet was taken, and he remembers an officer coming into his cell to give him the $30 they'd found inside. The officer stuffed the money in his pocket, George said, and left with the cuffs still locked tight.

Our lives have changed since 9/11, and mistakes will happen. But when government personnel put an innocent person through something like this, it would be nice if someone offered an explanation, or showed just a touch of humanity.

Until then, check your flash cards with your luggage.