It's depressing how often it happens. I frequently see ground staff trying to wheel-spin, wheelie or do donuts and hand brake turns with the baggage trolley tugs, and have seen the baggage belt, ambulift and catering vehicles driven into the side of the aircraft so many times a week that I lose count. So many of the ground crew just don't give a damn because they're not smart enough to understand how fragile an airframe is or how much stress it's under in flight. The sad thing is how it lowers perceptions of ground crew, because a lot of them are smart and conscientious but reap the disdain earned by the morons.