Copper spools have the sheathing stripped off, wire cut to reasonable lengths, then brought to multiple recyclers in stages.

To be sure, the odd idiot will show up with a unadulterated spool and try to get paid, but most that go to the effort of abducting these things off the side of the road aren't entirely stupid.

Then again, a less scrupulous yard might still buy the spool as it comes and strip it themselves.