I have to dissagree, stores generally do a good job of storing things safely in stores, once you have taken something from that storage area, you have to be responsible for it. If I walk swiftly thru a store I may see a cart with someone standing there but I might miss something as small as the end of a corner bead. I would immagine with the weight of the cart behind it, it would hurt to walk into one. When people get hurt they often have something to say, fair or not. If you were pushing your cart and saw him coming you would have been resposible enough to make sure he didn't hit it. So is it to much to ask for people to think safety and turn the cart so that sharp object can't be run into.
Everyone is responcible for safety no matter where we are.