It's true that at Costco or Sam's, such verbiage may exist in your membership agreement that you must submit to the inspection of a receipt cop on the way out the door. It has to do with the fact that these stores are not open to the public, but are 'clubs' open to 'members' and an inspection from a receipt cop gives them the legal right to inspect your property upon leaving the store.
I say 'YOUR PROPERTY' because a moment before going to the door, the merchandise became YOUR property after the transaction was completed. YOU are now the owner of what YOU bought. It no longer belongs to the store, even if you're still in the store.
So if the store is 'open to the public'...and you have not signed any agreement in your membership clause waiving your right to avoid search and seizure...... then YOU DO NOT HAVE TO STOP to show your receipt to anyone.
One retailer is notorious for this...the same one that canibalizes off the government and makes the customers work for them by having only self-checkout available at certain hours of the day.
The 'Greeter' has now become a little less friendly and has the job of also becoming a receipt cop.
But guess what... you don't have to comply. You don't have to wait in line behind others just to have someone rummage through your property.
You have every right to refuse to be searched...and that includes the person at the door checking receipts.
Not only is this one greedy, stingy company notorious for violating every right under the sun, but a well-known electronics/appliance store tends to do the same thing.
You have every right to say 'no thank you, have a nice day.'