It's kids that bother me, we had to pick a few things like shelves up last Friday night and there were a number of kids in there running riot. When we were at the bit of the marketplace with all the flat back storage boxes a little boy came flying round a corner from nowhere and bashed the side of his head on the front of our trolley (we were static as we were looking at something). His dad was about to say something to my OH, but OH told him he should be supervising his boy before he could get a word in. I also hate it when parents allow their kids to stand and jump around in the trolleys, as we had an incident where we lived in London years ago where someone let their kid do this in B and Q and a load of plaster mouldings fell on him and killed him. There were also 2 kids in the warehouse on Friday night where one was on the boxes on a flat bed trolley, the other one was running up and down the aisles with him at speed and there were no parents to be seen.
Sorry to be ranty, but it makes me furious, it's not acceptable in restaurants either (although I save that one for back in the UK, parents seem to absolve themselves of looking after their little darlings when they are about to sit down to dinner).