High capacity magazines are created for one purpose: to facilitate a person murdering as many people as possible at one time without reloading their weapon. They have no other purpose in sport, self-defense or law-enforcement.
Furthermore: assault weapons, which are designed and built for use by soldiers have no place in civilized society. Their only purpose is to allow someone to murder many people at the same time.
These products do nothing but facilitate gun violence among citizens, and sale of them to any non-military and non-law enforcement individual should be banned.
The federal government should also set minimum standards for states to license gun owners and guns at least to a level equivalent to those laws the DHS requires states set for issuing drivers' licenses.