I used to love shopping at this Walmart. No longer. They have instituted a practice of checking your receipt if you have unbagged items that won't fit into a bag as you walk out the door as if it were a Sam's Club. Simply put, they not only don't trust their cashiers, but they also don't trust their customers. I have never seen this practice done anywhere in the US outside of the wholesale clubs. I think it sends a bad message and discourages shopping there. I know I will quit coming there to shop.
UPDATE
Ok so here's what I've learned about shopkeepers privilege. Unless Walmart has probable cause that you have shoplifted something, you are under no obligation to show them your receipt. This is different for membership stores like Sams Club. If they try to detain you for not showing your receipt at Walmart and they have no probable cause to think you are shoplifting, then Walmart can be sued for false imprisonment. So I encourage all my fellow honest shoppers to simply ignore these requests to see your receipt. You are under no obligation to do so.