This happened to me a few weeks ago while I was grocery shopping with my roommate at walmart. A fat girl was talking to her fat friend, clogging up the walkway. They didn't have their backs to me, and they could see that I was coming down the freezer aisle that they were in the middle of. They made no attempt to get out of my way, or move to the side. But, they left me just enough room to slide right between their carts so I squeezed through at my full walking speed of about 3.3 mph. My roommate, who was behind me, later told me that she said, "he is so damn rude" after I walked off. Made me feel good.