Earlier this year I had to get rid of some manurite tubing that is high in Nickel and Chromium. It added up to about $20,000 worth of metal. the first time I called the scrap guy about pricing, he asked me how I wanted to be paid. I think he was a bit relieved when I said "company check". I can't imagine getting away with stealing something like that. When I asked him about it, he had his stories about people wanting cash for rather large shipments of scrap.
Another time at another site, one of the operators caught a guy in a cadillac going through a dumpster full of scrap copper from a transformer. He drove off real quick before that operator could call any cops. The guard at the gate insisted he didn't let anyone it. Riiiight. He was replaced pretty quick.