Walmart customers are starting to notice what looks like tracking devices on the bottom of their shopping carts This would align with recent Walmart patented technologies related to “smart” shopping cart technology, which will include tracking shopping behaviors of customers. They even patented a cart handle that tracks biometric data like heart rate, temperature, and stress levels Another Walmart patent described a system using invisible substances (e.g., oil-based or wax-based markers) on store floors that rub onto cart wheels, allowing Walmart to track cart movements by photographing wheels at checkout. This was aimed at mapping customer paths to optimize store layouts and advertising without explicit customer consent A Reddit thread said these are for wheel locking which is completely false as the wheels already have locking mechanisms and this new box doesn’t connect in any way to the wheels