Just before the attacks of 9/11, a terrorist that had planned to participate in the hijacks was prohibited entry into the United States by an alert immigration officer, who said he got the chills from the guy. Not exactly a scientific method. Later it was confirmed that he had been correct in his assessment. The same terrorist was caught in other actions and is now in prison. The immigration officer would be considered racist for his racial profiling. But he picked out thre right bastard, even though he was Arabic.