I'll be honest, I understand exactly where you're coming from, but is what he's doing hurting anyone? He's just tracing to build precision, not to spite anyone. He's not even distributing for profit, or claiming the works were his. He even showed the original. Nobody's being hated on, we all seem to just be lost in translation with what we mean. I, for instance, practice guitar by playing Master Of Puppets by Metallica. As for having to acquire permission to use ones work for simple practicing purposes, I doubt Lars would let me even if I could call Metallica and be like, "hey, gonna practice playing Master Of Puppets to get better at playing guitar so I can eventually write my own stuff." It's impossible. For two reasons, Copyright is very heavily covered by Metallica because Lars threw an (understandable, yet immature) tantrum over Napster. The reason they had a problem is because it was offered for free, when originally you had to pay. Did he have to pay to use them as reference/trace work? No. So really, isn't this uproar kinda silly and unnecessary?