I work in a retail store and I do various things depending on where I'm needed. In this instance, I happened to be handling returns. So a customer brings back an item and everything goes well until I hand him a paper and kindly ask him to write down his name, address and phone number. The reason we do this is to be able to contact the person if something goes wrong with processing their return. He doesn't fill out everything, just puts down his name.
Me: Um, sir, could you please--
Guy: No. I have no obligation to give you that information. It's private and it's my federal right to keep it that way.
Oh god, here we go.
Me: Sir, the reason we ask for it is just in case we have a problem processing the return, we need to be able to contact you somehow.
He goes on to mumble and grumble about how ridiculous this is, honestly to me it's not that big of a deal, we don't send junk mail or anything. Finally he ends up just putting down his phone number and goes,
Guy: That's all you're getting from me.