To me, I don't get how people get away with this kind of things. My uncle is a general contractor. If a client is being unreasonably difficult with payment, he'd simply show them photos of random dead children and photos of their kid's school building. The scary thing is, he actually have the goons to carry out such a job although he said he'd never go through with it. He said the most he'd done was break a client's leg and even that was only one time when he was still small time.