If a person cannot hit what he or she is shooting at in ten shots, he or she needs to practice. If a home is invaded by more people than a person can defend with ten shots, that person is in serious trouble no matter how many bullets they have. There is zero reason to have these except to inflict as much damage as possible or because someone is too lazy to reload. In target shooting, an over-sized clip adds extra weight and effects the balance of a - true sporting and target weapon. Again, if the person thinks he or she needs these clips to protect himself from the evil government coming for him, I have a documentary film for them. It's called Men in Black.
So what do we do about the clips already out there? We cannot really ban them, but we can make them illegal to use anywhere but on a shooting range. We add to the jail time of any person who is caught using an over-sized clip in the commission of a crime and we hold accountable the people who have them in their possession. If someone owns one of these and a shooter gets a hold of it, the owner of the clip can be held responsible for not making sure it was secure. In other words, own these clips at one's own risk. These clips are not protected the second amendment and I believe this is one ban that could make a difference.