The weapons are already legal. What is illegal is selling them to an ineligible person. In this case there was all kinds of evidence that the guns being purchased were going to be used by someone other than the purchaser. That's illegal. Beyond that, there was reason to believe that the guns were going to be used by people who intended to use them for criminal activity. That's not only illegal but is also flat out stupid. On top of THAT it appears that this illegal activity was being conducted with the intent to manufacture evidence to support a political goal of restricting private ownership of semi-automatic weapons. That is tyranny.