You're right. It's not the norm. As a teenager, a close friend of mine worked at McDonald's and she always told me about one specific officer that would come through drive thru and before ordering, would announce to her that he was a policeman. Once he got to the window, he would be in his car and uniform so she wondered why he always felt the need to tell her he was the police before ordering. I've always been embarrassed to know the guy and guys that EXPECT something free or even argue about not