I tried Walmart's self-checkout to see if it was as frustrating as some shoppers say. Here's what I found.

• Walmart shoppers have told me about their frustration with the retailer's self-checkout security.
• In particular, I've learned that some moves trigger an alert, even if you're doing nothing wrong.
• When I tried to trip the alarm, I was surprised to see that the tech simply worked.

Ever since we published a story about Walmart's missed-scan detection technology in its self-checkout kiosks, my email inbox has had a steady stream of responses from frustrated customers.