You suddenly begin noticing signs bearing Arabic script in buses. What do you do? Well, what bus riders in Richmond, Virginia did was call the local Transit Authority to find out what it might know about the signs, which had been turning up on buses and the walls of local universities. The Associated Press and other media outlets subtly scoffed at the concerned citizens, explaining that the Arabic phrases were in fact innocuous - translating as things like "paper or plastic?" or "paper, scissors, rock" or "I'm a little teapot." Those translations in fact appeared at the bottom of the signs, along with admonishments like "Misunderstanding can make anything scary" or "What did you think it said?" The provocative ads were the work of the Virginia Interfaith Center, which placed them in public venues as part of an effort to change the fact that, as the center's executive director put it, "as soon as people see Arabic, they immediately make an association with terrorism." Orthodox Jews like me have considerable experience with bias, and sympathy for good-willed, law abiding Muslims who are victims of religious prejudice. We know well what it is like to be targeted by bigots for harsh stares, ugly comments and worse. I always carry the realization that some subset of society will, when seeing my beard and headgear, associate me with Shakespeare's Shylock, Dickens' Fagin, the fictional poisoners of wells or the fantasized Elders of Zion. And those are all, in the end, imagined characters. In this age of all-too-real and widespread Islamist terrorism - where the Muslim faith is regularly invoked by people around the world as directing murder and mayhem - innocent Muslims surely feel even more marginalized as a result of the hasty generalizations people tend to make, and bear the bitter fruit of the suspicions and fears born of their coreligionistsâ€š all-too-real words and actions. BUT THERE are times, still, when suspicion and fears cannot be dismissed as the products of bias, and can even rightfully lead to the curtailment, at least temporarily, of the freedoms we Americans enjoy as our birthright. Like the recent case of a group of imams who were removed from a flight about to leave Minneapolis-St. Paul International Airport for Phoenix. That the Muslim religious leaders had reportedly prayed loudly in the airport before the flight was certainly no reason to consider anything amiss. But when passengers and flight attendants told law-enforcement officials that the imams had switched from their assigned seats - to a pattern associated with the September 11 terrorist passengers: two in the front row first-class seats, two in the middle of the plane in aisle seats and two in the rear of the cabin - security officials' concern was not outlandish, as later was charged by a number of American Muslim groups. And when three of the men then asked for seat-belt extenders, despite being of average build, and proceeded to place them, unused, on the floor before them, it was hardly religious bias - or, in the words of Representative Sheila Jackson-Lee (D., Texas), "racial profiling, harassment and discrimination" - that motivated police to detain the group for questioning. No weapons in the end were found among the imams, but that happy fact does not mitigate the less-happy one that the authorities' actions were more than justified. As a visibly Jewish man, whenever I am on a plane or train, I always consciously try to alleviate any discomfort others might have with my own appearance or actions. Even well before September, 2001 - even before a young lady at a bus stop asked me to please tell her cowering 5-year-old that, despite my in-need-of-a-trim beard, I wasn't Osama bin Ladin - I would always make sure to apprise seatmates, with a friendly smile and a pleasant demeanor, of the fact that I was about to say my prayers, and that my swaying and whispering were only parts of the ritual. And Orthodox Jews, to the best of my knowledge, haven't ever hijacked airplanes. It is unfortunate, but Muslims who disavow the hatred and violence preached by some of their coreligionists have to accept, with sadness but pragmatism, the burden of society's suspicion-by-association. It's a regrettable reality that actions they take in all innocence might be misconstrued at times as sinister - or that Arabic script suddenly appearing in public places might cause some alarm. But our world is, as they say, what it is. Yes, sometimes things that seem frightening in fact turn out to be harmless. But fright can also save lives and limbs. "Fear itself," unfortunately, is no longer the only thing we have to fear. The Virginia Interfaith Center would probably consider me in need of re-education. But, with all due respect to the group and its well-meaning efforts, for my part, I still think that when I see something, I'll say something. The writer is director of public affairs for Agudath Israel of America.