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.