alt Hacker NewsIt's in the article linked
> When buying groceries—food and non-alcoholic beverages, pet food or supplies, disposable paper or plastic products, soap, household cleaners, laundry products, or light bulbs—you must be charged the lowest displayed price, whether on the sticker, scanner, website, or app.
In Australia, when scanners became common, the law was "in the event of a mismatch, the consumer gets first item free, and any subsequent items at the lower price".