The 1988 Supreme Court ruling California v. Greenwood created legal precedent for dumpster diving. Under the ruling, anything thrown away in a public space is fair game. This kept the poor from being prosecuted, but it also opened the door for dumpster divers and treasure hunters.
Yes, hobbyists. Wired profiled a man who flips corporate trash as a side job, and makes three figures doing it. And while consistency counts, it's the big-ticket items that are really jaw dropping.