I guess Norm himself would be in trouble there as he spends his time frequenting museums and ripping off designs. Presumably he seeks permission from the curator but what about the person (or the estate of the person) who designed them in the first place? Not only is he making them himself but he is also encouraging millions of people to make a copy too.
If you make an exact copy of a piece of antique furniture and attempt to pass it off as the original, there's no doubt that is fraud. If you make a copy as near as possible to the original because you admire that style and want to use the original construction techniques, is that the same thing? Don't thay say that imitation is the greatest form of flattery?