Originally Posted by KirStang

To answer your DC_Dux, the ATF has the power to track those weapons after purchase. They are charged with enforcing the sale and transfer of arms, and they may legally use their law enforcement powers to track and arrest such an individual.

In short, I think inaction by an enforcing agency is not sufficient grounds for new laws. Does that make sense? Not only can the ATF prosecute the individual for straw purchases, they can also prosecute him or her for dealing in firearms without a license. All the ATF has to do is build a case, as law enforcement usually needs to do.