A PG&E substation in Berkeley has a sign on the fence saying it uses “Proof Positive copper with TraceID technology”. Does that mean a scrap dealer can examine offered copper hoping to learn where it came from? Or that the police can learn? Scrap dealers are supposed to get ID from anyone that sells them copper, so the police know who sold them each batch?
They’re supposed to reject anything officially marked or otherwise hinky. Or especially if the guy selling it says he stole it - they often don’t. That’s an old article, but I chose it because it was a sting where the recyclers were specifically told it was stolen and only one said no 
. But this happens constantly just in the Bay Area. You can find busts all the time, including very recently. Some years back I was chatting to a fire marshal about a similar sting where they went to I believe 13 recyclers with steel ties stamped by railroads - 12 of the 13 took them. Scrap-yards and metal recyclers generally are often only one (or zero) steps removed from organized crime. It’s just too profitable to look the other way. A recycler down the road from my old workplace got busted with stacks of catalytic converters and bails of wire and shockingly, huh, theft of wire dropped off in the neighborhood (the thieves themselves presumably just temporarily moved elsewhere like a popup restaurant)
Also it can be hard sometimes to prosecute. They busted some cats in a car a couple of years back with 600 lbs of copper wire. The DA refused to prosecute because, hey - we don’t know where they got that wire. AT&T threw a fit over it because according to the tech I was talking to nobody else uses that gauge of wire in any quantity.
Proof Positive is a technology developed by a company called Southwire that has a serial number laser-etched onto the wire, allowing it to be traced. The serial number can be looked up on a web site, supposedly simplifying the process of identifying the source of wire being sold or recycled.
From the website: “…new technologies are making it easier for recyclers to instantly identify stolen copper, and in turn, provide law enforcement the hard proof they need to prosecute criminals.”
Great, but it won’t deter crooked scrap yards/recyclers.
Never understood why there aren’t many more sting operations to shut down these places.