Well, it's family name, too. You're just forgiven somewhat if you're outside the community and don't know which family is supposed to be given deference. Unless you're talking to a family of cops or the family that owns everything in the area, in which case you immediately agree with whatever political opinion they share (loudly).
Only when talking to people beneath them. When talking to your superiors, you should be deferential and circumspect.
American society is more hierarchical than a feudal aristocracy. It's just based on money, skin color, and gender instead of family name.