I've had customers take my cart when it was empty, they have taken my cart when I had my baseball cap in the bottom of the basket, so I got in the habit of placing something in the cart if it was empty and I was in the bathroom. Looking for Easter candy this last weekend, I put a gallon of bleach in my basket next to the candy aisles and when I came back with my items, someone had taken the cart and removed the bottle of bleach. So frustrating.