Actually, anybody, Arab or not, shouldn't be doing stupid things that will tax the patience and resources of edgy law enforcement officers who already have too much to do. I would think if you were Arab or Arab-looking you would at least try to be sensitive.
You know, if a bunch of tall slender blonde ladies had been engaging in terrorist activities, I would be darned careful about hanging around at public facilities. Though I belong to a racial/gender/ethnic group that's vanishingly unlikely to be engaged in terrorism, I'm still not going to bug the stressed-out PR office at Quantico Marine Base, where I would very much like to go see some open land that once belonged to my ancestors. I'm just going to let it be. They have enough on their plate right now. Let's show some tolerance for their problems. If a pack of young Arab idiots gets rousted because they did something fairly thoughtless, they have only themselves to blame.