"Self government can't work without self control."

There is an empty building near me. I don't know who owns it ... but I'm pretty sure it's not mine, so I leave it be.
Others have a different attitude. "No one's looking... so it must be mine for the taking." There lies the crux of the problem.

Education pays a role, only to the extents that:
A) I can see how the loss suffered by another impacts me; and,
B) Enforcement agencies see the harm, danger, and inconvenience such actions cause.

Even at it's most 'harmless' level, this is a 'quality of life' crime, one which, like littering or graffiti, seems to encourage more serious crimes. This idea was verified when NYC acted to clean up Times' Square.

It's never just petty theft. prosecutors and law enforcement have an entire arsenal of tools to use, if they wish. Theft, trespass, criminal damage to property are among the charges that may be brought. Any secondary damages ... for example, if the disabling of a stop-light leads to an accident .... can also be charged to the thief.

Finally, there is no denying that the scrap yard can make a difference.
Forget about the ID requirement ... once you're out the door, there is no link between you and the material. That ID requirement is there strictly for tax / accounting purposes.
Yet, the scrap dealer KNOWS his business. Of that there can be no doubt. If he wished to do so, he could either refuse a purchase .. or call the cops, when a suspicious product is offered. In Reno, certain scrapyards have done just that - resulting in several convictions.
As an example ... PoCo cable is rather unique. Naturally, the cable loss usually results in a power interruption, or worse (here wildfires are common). It's not that hard to associate a length of cable with last nights' power outage. If the scrap dealer acts, the crime is solved. If he plays dumb, and just tosses it in the pile .... all is lost.