Me: Ma’am, do you have a firewall?
Clueless caller: Yes, the chimney is to my left.
Me: No, no.. On your computer, is there a firewall?
Clueless: The computer is against a wall..
Me: Um. Oh, I know, do you have McAfee?
Clueless caller, excitedly: Yeah, yeah, I have that!
Me: Okay. Well, that’s a firewall.