IIRC, some of the first New Orleans residents to return after Katrina were the copper thieves. One of 'em was shot dead by a cop who thought the guy had a pistol stuffed in his pants. Turns out it was a *hacksaw* handle that was protruding from the idiot's belt. Good shootin', officer.
The most outrageous metal theft to date, though, has to be where all the aluminum bleachers were swiped from a schoolyard or park (can't recall the location).
I think there are organized rings of thieves for the big projects like the bleachers or perhaps the cell tower, but the key to lowering the rate is to pursue the crooked dealers.