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Comment by neuralkoi

1 day ago

Yesterday I went to Walmart, and at the self-checkout the system quirked out and an attendant came by. She reviewed some sort of draconian overhead cam video of me trying to locate a tag out for a product to scan. Gave me "guilty until proven" innocent vibes. Are these systems actually effective?

Hey, something I'm somewhat qualified to answer! So, yes, these systems are actually effective. The systems and procedures are designed to look low key, but essentially perform PRISM-like mass surveillance behind the scene. These systems are managed by former US IC personnel.

What happens is that your identity is tied to these purchases and after a certain threshold you get flagged as a thief, essentially. At that point, you will get very increased attention (via checkout, purchases, and floor walkers), and after another threshold, will be trespassed and/or prosecuted.

But, you'll probably get away with a banana or few before you trigger the loss prevention threshold.

  • It flagged my for entering quantities of an item instead of scanning each individual item. It wouldn't let me pay until a human looked through my bags. There is a quantity key. I used the quantity key.

    I'm not sure it's the super system it's sold as.

    • As a former cashier it kills me to scan one at a time, the self checkouts all have painfully long mandatory wait times between scans. Most of my time is just spent holding back my muscle memory, or getting yelled at for trying to scan at a normal cashier scanning pace.

  • On the other hand Walmart has been getting rid of self checkout because they're not actually effective.

  • How is your identity tied to the purchase if you are using contactless payment (e.g. Apple Pay) that produce an anonymous DPAN?

  • But what if you don't steal anything but the system is messed up. I had a case where I bought multiple things at a big hardware store, self checkout of course, and on my ticket was something I didn't notice. Because I bought a lot I didn't notice until a month later when I looked at the ticket and returned something else. Should I tell them or not, will I be some kind of weird situation?

    I hate self checkout.

    At my grocery store, it very often complains about something when I'm checking out. The person comes over, reviews the video and said you aren't doing anything wrong.

    The answer is don't go to places where you self-checkout, and don't go to places with surveillance. There are still a couple of grocery stores in my town like that.

    • In the fraud/theft detection I had some experience with, everyone learns right away that mistakes happen all the time. Singular incidents are basically not worth investigating unless something about them is highly unusual, like an unusually large dollar amount or aligning with a scam that has become popular.

      When I watched movies and TV shows I had this idea that thieves were all clever people who built smart systems to evade detection and steal right out from under big corporations. Some of those people might be out there operating undetected, but the average thief who gets caught is someone trying to abuse something as much as they can until they get caught. Some of them are so brazen (like the scan everything as bananas post above) that they must believe that nobody will ever check and if they do get caught nothing bad will happen.

      The staff who watch these things have a good sense of what dollar thresholds the customer must cross before getting law enforcement involved.

    • I've had awkward interactions with the Walmart system. It's clearly using a neural net, and a good one at that. It's only ever flagged me when I did something odd (like put something bagged and paid for in my cart, then take it out, then put it back again). I dress/groom like a thief, so the conversations with the staff are always annoying.

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    • Honestly, I trust these systems more than humans to do the same work. While we're all talking anecdotes, this one time at Walmart (how all good stories start) many years ago I was in the music section and these two in-store security guys approached me, saying they had told me to never come back in the store, etc., making a big scene. I so rarely go to Walmart and found the situation kind of humorous and wanted to see where it would go (knowing I had not done anything wrong now or in the past). They had seen me on video evidently and thought I was somebody else - serial shoplifter or public urinator or who knows what. Anyway, I tell them I've never been told to leave prior to this visit, didn't know what they were talking about. They were adamant that I was in the wrong, asked me to come back to the office while they looked into things. I was like, "sure!", more entertained than upset. So there I am sitting in the office while some guy combs through video footage. A guy of authority comes in, tired demeanor, asks these guys - well, did you match his ID? "No", says he. Checks ID, realizes I'm not their guy. Many stressful apologies on their behalf. But that's humans for you.

  • Target keeps a file on you until you've stolen an amount which constitutes a felony.

    • Yep, same thing with Walmart. I don't know about Target's systems, but wouldn't be surprised they're on par. Walmart is one of the biggest leaders in loss prevention and customer surveillance.

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The self checkout at my preferred grocery store (Hy-vee, an upper midwest chain) has started using these overhead cameras to confirm that you're purchasing everything you ostensibly have in your cart. Except it always flags us for the Starbucks drinks we're carrying (Hy-vees usually have a mini Starbucks shop inside them). More annoying though is that it flags us for the 5 gallon water jug refills that we manually punch into the self-checkout kiosk, because the surveillance system isn't satisfied unless the heavy ass jugs of water leave the cart, slide across the scanner and then get placed in the bagging area – anything else is possible theft.

All this has done is train us to keep the carts out of the camera's viewing angle. It doesn't care if you keep pulling handfuls of groceries out of hammer space, as long as there's no cart in the frame.

  • I don’t use self checkout systems that have weighing scales that require items to be moved from the cart to the bagging area. I either avoid self checkout at these stores or stop going to such stores altogether. I shop at my neighborhood Whole Foods and Home Depot; the self checkout systems don’t have this requirement.

  • My decision on whether to use the self-checkouts at Costco often comes down to "do I want to remove these heavy items from my cart?"

I'm in Australia but similar sounding system is in operation at our two major supermarkets.

I scanned a drink, heard the beep, put it in the bag. I scanned a loaf of bread, heard a beep, put it in the bag.

Now, instead of the typical "Unexpected item in the bagging area" it now shows the overhead replay and locks the system out until an employee comes over to review.

Combined with their exit gates that don't open if they think you've not paid for something, and cameras that track you through the store it's feeling very unfriendly.

Sam's club has 'the arch', and one time when I did self checkout I did miss an item (thought I scanned it and I didn't apparently) and so far that's the only time they've actually checked the cart, the rest I was just waved through.

So seems pretty good. Obviously erring on the side of having an employee double check makes sense when their profit margins are generally single digits. One missed tshirt means they lost money on your $300 cart.

  • Well, Sam’s Club and Costco are kind of their own things since they’re members only, you sign an explicit agreement with them saying it’s fine for them to look at your cart, and if you refuse they can just revoke your membership and refuse to do further business with you. You’re under no obligation at Walmart or Target to get your receipt checked, although most people are polite and fine with it.

    Personally, I always just say “no thank you!” and walk past the receipt checker at non members stores. They know me at Walmart and know I’ll refuse the receipt check and stopped bothering me.

    • The explicit agreement also says that you'll return your shopping cart to the coral, and see how well that works.