Guido Menzio, an economist at the University of Pennsylvania, was pulled off of an American Airlines regional jet from Philadelphia to Syracuse because he was doing math.

Flight from Philly to Syracuse goes out on the tarmac, ready to take off. The passenger sitting next to me calls the stewardess, passes her a note. The stewardess comes back asks her if she is comfortable taking off, or she is too sick. We wait more. We go back to the gate. The passenger exits. We wait more. The pilot comes to me and asks me out of the plane. There I am met by some FBI looking man-in-black. They ask me about my neighbor. I tell them I noticed nothing strange. They tell me she thought I was a terrorist because I was writing strange things on a pad of paper. I laugh. I bring them back to the plane. I showed them my math. It’s a bit funny. It’s a bit worrisome. The lady just looked at me, looked at my writing of mysterious formulae, and concluded I was up to no good. Because of that an entire flight was delayed by 1.5 hours.

I’d note that this is an hour and a half delay on a flight that’s scheduled at 1 hour 5 to 1 hour 21 minutes. It’s fortunate for him that he was ultimately allowed to fly. Frequently passengers that are removed are put on later flights even when there’s nothing of real concern.

This just underscores the idiocy of “see something, say something.” As Bruce Schneier often says, when you encourage amateurs to do security you get amateur security.

On the other hand as Alex Tabarrok observes, Algebra has “Arabic origins plus math is used to make bombs.”

Update: The Washington Post has more,

And then the big reveal: The woman wasn’t really sick at all! Instead this quick-thinking traveler had Seen Something, and so she had Said Something. That Something she’d seen had been her seatmate’s cryptic notes, scrawled in a script she didn’t recognize. Maybe it was code, or some foreign lettering, possibly the details of a plot to destroy the dozens of innocent lives aboard American Airlines Flight 3950. She may have felt it her duty to alert the authorities just to be safe. The curly-haired man was, the agent informed him politely, suspected of terrorism. …The woman never reboarded to the flight, Menzio said. No one told him, though, whether she was barred from returning or stayed away voluntarily, out of embarrassment or continued fear of the “dangerous wizardry” his mathematical notations resembled.

The Post though describes the Philadelphia to Syracuse flight scheduled for a 7:20pm departure as “the first leg of a connecting flight to Ontario” but I’m not sure that makes sense.

The Ontario in question refers to Canada. There’s no Syracuse – Toronto flight that would connect without an overnight. His ultimate destination is described as a university in Kingston, Ontario — which would mean flying through Toronto — or more likely a two hour drive. My guess is that he wasn’t connecting.

Update 2: I’m reminded of this post from 13 years ago.

At Heathrow Airport today, an individual, later discovered to be a school teacher, was arrested trying to board a flight while in possession of a compass, a protractor, and a graphical calculator. Authorities believe she is a member of the notorious al-Gebra movement. She is being charged with carrying weapons of math instruction.