If you ever do visit a Fry's again, the trick for that "let me check your receipt and mark it with a pink sharpie" person is to just smile and walk right by. They won't stop you or question you, because they have been trained that it would be unlawful to do so. They can ask to see your receipt and check it, but they can't demand it.

More than once there has been a line of a half dozen people at the pink sharpie exit, and I've just walked on by, much to the amazement of the people waiting in line.

Note: I'm talking about Fry's, not Costco. I'm told Costco is different because it's a membership club and you have to agree to their terms and conditions to shop there. (I'm also told that even Costco can't demand to see your receipt, but they can cancel your membership if you don't show it.)