Except this ruling specifically calls out unlicensed machine shops, associations and societies. These entities are not engaged in the business of building and distributing firearms. Now it seems the ATF does consider them in the business of building firearms if they offer their facilities and tools to individuals seeking to build/finish receivers. The conveniently vague associations and societies definition could be applied to anyone. It was already illegal for FFLs to build unregistered firearms. There was no need for this ruling unless they intend to make it illegal for private individuals as well. Just my opinion of course.