This activity has gone on for years all over the US. In 1989 I toured an old substation near downtown Houston. Thieves had been "mining" it by taking fireman axes and cutting out old paper and cloth insulated copper cables of abandonded-in-place circuits. They were caught after they tried one that wasn't abandonded. IIRC, there was a body to be recovered. The floor was littered with little chips of copper from the chopping.
In light of the way things are today, it was also instructive as to how easy it would be to disable everything in a wide area, if a terrorist were so inclined. Evidently, no one's watching these places.