People who ride their motorbikes on the pavements.
Ok, so the postmen-on-motorbikes are absolutely fine, I understand they're doing their jobs, but randoms who ride up the pavements on their motorini, is that really necessary? What's wrong with the road?? The car drivers try and run me over when I'm crossing the road, and then those muppets on motorbikes try to run me down when I'm on the pavement! Is there no escape??