I feel very safe in my work building, because we have a vigilant security officer in our lobby. I'll often see him scrutinize people as they enter the premises. He doesn't give everyone the twice-over, just a few select individuals who he must adjudge to be more of a security threat than others. I'm not sure exactly what kind of profiling technique he's using, but I have noticed that the vast majority of those he examines are blond, attractive females in their twenties.