First, William M. Briggs, Statistician to the Stars!
Firearm Homicides Dropping. Assault Weapons Ban Not Correlated With Decrease In Homicides. No Need For New Restrictions.
Darwin Catholic, on the whole matter:
Assault Weapons Part 1: Battle Rifle to Assault Rifle
Assault Weapons Part 2: Assault Rifles vs. "Assault Weapons"
Assault Weapons Part 3: Gun Control
I'll add that beyond target shooting, high capacity semi-automatic battle carbines are the deterrent weapon of choice for (say) a single shop proprietor or home owner, faced with a rioting mob. This is all the more so if he's using highly frangible rounds, which do not have overpenetration issues.