In this age of tech-centric retail, maybe we really do need the human touch to keep us honest. According to a recent article in The Atlantic, self-scanning in supermarkets is turning into self-scamming, as shoppers switch barcodes or ring up expensive by-the-pound items with the code for a cheaper per-pound item. That last bit of “external shrinkage” is referred to as “the banana trick.” As the magazine said, you know there’s a problem when a whole new lexicon pops up around an issue.

As consumers are demanding their food delivered in faster ways, self-checkout scanners appeared to be the way for tech-savvy people to skip the lines.

But there’s a cost to do-it-yourself checkout, the magazine reports. About 20 percent of shoppers answering an anonymous survey admitted that they had stolen via self-checking. And an earlier study of one supermarket found that out of $21 million in sales, $850,000 worth of food and other items were placed in paper or plastic and taken home without being paid for. So why is the five-finger discount more acceptable to people who would normally never steal when they scan groceries themselves? According to a comment on Reddit, one reader detailed the rush he received from bagging an item that wouldn’t scan and leaving the store. It’s the same risky behavior teen shoplifters claimed in bygone eras.

Another earlier report, cited in the U.K.’s Guardian found that people who are usually honest resort to theft simply because they can, and don’t feel it’s as morally wrong when there is no human interaction. The other dynamic at play here is that self-service can be frustrating and if an item isn’t scanning correctly, it’s easy to toss it in the bag and call it a sale.

From self-scanners, we’ve evolved into Amazon’s checkout-free grocery store, which uses cameras and sensors to track shoppers’ purchases that are then charged to their Amazon account. The trick is to record what’s actually removed from the shelves, and what is returned. The technology is similar to the sensors used in hotel minibars, except in a hotel room there are no cameras to record removal and return of those little liquor bottles.

And while the technology is to help out with the rising cost of labor, as well as the shortage of qualified workers, it may be cost effective to keep some humans on the payroll to keep everyone honest.