I recently bought a 250-foot bulk box of Cat6 to do some custom-length Ethernet runs through my house, and I did what a lot of people do: go to Amazon, search for the product, buy the one at a decent price and a plethora of reviews. When I stripped a conductor and dragged a knife blade across it, the copper peeled away to reveal that the cable was actually copper-clad aluminum instead of solid copper, which wasn’t immediately alarming, because the cable and listing were marked as such with “CCA.”