Once they start, everyone will do it, that keeps them from being un-PC and 'profiling' anyone. If the 4th Amendment was really in force, they could not search my bag, or ask me about where I'm going and why. No matter what, I always tell them I'm on my way to shoot a porn movie. If they ask the title, I tell them "Sluts in Uniform Volume 8, Did you see Volume 7, lot of people really liked it." They never ask anything else.