In some states in the US you can return your cans/bottles for a fee. This fee was added to your purchase and you redeem the fee by returning the can/bottle.
The process of collecting your fee is automated by a scanner, that scans the barcode. Not all barcodes qualify for a refund of the fee.
If hypothetically a canned drink that does not incur the fee upon purchasing the item is returned experimentally and found that the machine registers a refund, (or if a store does not charge a fee but another store honors the product for a fee) is it ethical to collect refunds on a product you were never charged a fee to begin with? Especially ongoing, deliberately making a profit on something that may never be discovered?
Would there ever be a situation in which this would be ethical?
(I see no issue returning someone else’s cans/bottles and collecting their fee because a fee was paid to begin with and they have forfeited the right to the fee by disposing of the can/bottle without returning it to redeem the fee. technically you’re supposed to return the can/bottle to the same store you purchased it from).