I had to work in a $7M house where we delivered all the appliances, a week later the guy calls (he's a house husband, the wife works) and he wants us to install an anti-tip device in his CASED-IN SubZero refrigerator. The anti-tip device is basically a block of wood, wedged between the cabinet and the top of the refrigerator. Made us take our shoes off and everything.
Well the fridge was full of food. So it was even heavier, he made us put down cardboard for the casters. So we do that, roll the fridge out, install the wedge, roll the fridge back into place...pick the cardboard up and the casters had left impressions in the floor from the corrugations. He was still having a duck when we left.