If they really want to home in on metal thieves, they can deal with at the scrapyard alone. They don't need to burden everyone else.
It is a slight burden on scrap buyers, but the ones that buy from walk-in types are crooked and play deaf, dumb, and blind and buy it to make a buck even when they know that a person like the seller should not have manhole covers, highly machined bull gears, brass gears, copper, etc. If scrap buyers had integrity and turned down the copper thieves, there would be far less invasion and stripping.
A thief stole a highly machined, high price brass gear my father had in surplus and took it to a scapyard and sold it. The sheriff's detectives tracked it down by canvassing scrap buyers. The thief is serving time now and is paying restitution of pennies per day based on prison labor. The people that bought that gear converted it to cash as soon as they bought it from the thief, and they are effectively complicit in his crime. They knew that a young dipstick meth tweaker like him would only have such an expensive machined gear if he stole it.
