We had a problem in my country a few years ago where large numbers of people would buy up a heap of baby formula so that they can resell it overseas at a massive profit. Enough that stores had to put caps on how many you’re allowed to buy, and local parents still frequently couldn’t get their hands on it.
They weren’t generally stealing, but if they were, you bet I’d report that. And if they were noticeably going back in to buy more than the limit.