Let me take you out of context...
lets say you have no concerns about shooting your family or neighbors
If you were to use such a weapon in a home defense shooting you would be probably be taken to pieces in a civil case provided the local law enforcement decided that it was a clean shooting and didn't press criminal charges.
Now before someone comes in with the "We have a castle law in my state so I can shoot anyone I please if they are in my home." Most castle laws don't protect you from a charge of negligence. That is exactly what they will use against you in such a case. "You have no concerns about shooting your family or neighbors, when someone comes in your home you hose them down with a submachinegun." A few lines like that from a savvy lawyer and 12 of your peers will be thinking you should be giving Joey McCrackhead's wife $200,000 for your negligent behavior.