I don't throw a fit about it, but I don't like it. The problem is that for the store, shoplifting is a problem, but statistically, very few customers shoplift. So they take action to reduce loss by essentially treating all their customers as potential shoplifters and asking them to prove that they're not. Do you really not understand why people might resent that?
No I really don't understand. All customers *are* potential shoplifters, it's a huge and pervasive problem, why shouldn't they assume that I might be one too and check? I mean it's a simple receipt check, not a body cavity search or patdown and I would bet it is a significant deterrent. Like I said, mountains out of mole hills, it's borderline mental illness to get upset about it.
It's no different than having to show ID to buy certain things, to enter certain establishments, to rent a car or to take out a loan. Most people are who they say they are but enough are not that it's prudent to verify. It's not an accusation of wrongdoing or deception, it's just common sense to trust but verify because we all know that every human is a potential liar/thief/etc. Anyone in doubt of this, just leave your wallet unattended for 5 minutes in any public place and see if it's still where you left it when you return. I'd bet that more than 80% of the time it's either gone or any cash it contained has been liberated.
I will add that I do occasionally become annoyed by receipt checking at places like Costco but it's strictly because there will be a big queue of people trying to exit the store with their purchases while just one or two checkers are carefully inspecting the receipts while chatting with customers. At these times I think come on, get on with it, just glance over the cart for any big ticket items and call it good.