It might be desperation honestly. People looking for anything they can get for free to sell online for some extra cash. These are hard times we live in 🥴 not condoning your issue but hopefully sharing some light as to why it happens. I noticed you said in a comment that you’re a household item store- household items can be pricey and not everyone can afford what they need. They might see dumpster diving as an easy way to either one, get the necessities they can not otherwise afford, or two, resell items to make some extra money. Of course, there’s probably other reasons I didn’t list, but I would assume those are the most common ones?