Selling used copper wire to the scrap yard
Where I live, there was a high amount of copper and aluminum theft from abandoned and foreclosed properties, as well as from new construction sites. There now is a law which requires a building or demolition permit be presented at the time building materials are sold for scrap. One local scrap yard "forgot" to get this information and was shut down. This has basically eliminated the theft of small quantities of aluminum and copper since there is no way a person with a shopping cart of copper pipes and aluminum siding can sell his materials locally.
The requirement for a building or demolition permit greatly reduces the chances that a home-owner who has stockpiled used copper or aluminum for years being able to sell these items without trucking everything from the area, and often with increasing gas costs, it become unaffordable, so everything goes to the dump (where it isn't recycled) or into the city recycling program, where at least it gets recycled, but the city gets to keep the money for scrapping.
Unfortunately, there now is a new, more organized house stripping group who come in with legitimate looking remodeling trucks and strip out houses. They sometimes go so far as putting advertising signs "Home repair by Acme Home Inprovements" or whatever in the yard, mowing the grass, planting a few flowers (which are stolen overnight from a nearby garden center), paint a few windows and the front door, trim trees, and make other obvious "improvements" which nearby neighbors see as legitamate looking improvements. Of course, the neighbors assume that someone is finally taking an interest in the abandoned property, and don't ask any questions. Meanwhile, every shread of siding is taken from the sides and back of the home, and every piece of copper wiring and piping is also stollen. After spending 4-6 hours, the work crew takes off, never to return. Eventually neighbors get suspicious when days or weeks go by with no further "improvements" and when the police are finally summoned, the theives are long gone, often selling the "scrap" materials out-of-state.