Bogie is right about not accusing folks who look like Middle Easterners. I remember attending the Oktoberfest in New Braunfels, Texas shortly after the Iranians took the embassy hostages. As the beer flowed, the crowd got very ugly, chanting "Death to Iran!" I worked at that time in the foreign students office at the University of Texas, and there were a couple of guys that I recognized as Iranian students. They had a look of abject terror in their eyes as they tried to get away from the place. My roommate, who was of Czech extraction but had the misfortune that evening to have olive skin and black hair, was threatened by a couple of goons. We left immediately; it was very unpleasant and very scary.
While I would not ever condone what the revolutionary Iranians did, those guys I recognized weren't revolutionaries. They were just students. Years later I found out that my (future) wife had an Iranian girl as a housemate who was in the U.S. and could not go back because her father was hanged in Iran because he was B'nai Brith.
We must take decisive and strong action over this, but we must not overreact.