Does "assault weapon" mean anything that can be used as a weapon to assault another person? Like baseball bats, 2x4s, steak knives, cars, steel pipes, odd objects d'art, folding chairs, fertilizer, fire arms, etc? Sounds extreme to ban all of those things. Maybe we should just outlaw murder and assault.
Oh yeah? Sure its for self defense. What if someone gets an assault rifle for the purpose of "self defense" and then uses that to kill someone? Sure other people with guns might kill the aggressor. But what if that guy already killed someone? Just one person. What if that person was you? Or one of your family members?
And that stupid argument that says we need to outlaw every other thing that could kill or harm people (i.e. gravity, knives, bats) if we ban assault weapons. Just think this way. If you were going to kill a bunch of kids in a school, what would be your weapon of choice? A knife? A shotgun? A pistol? A piece of wood?
Maybe something that can spit out the most projectiles per second? i.e.
An assault rifle? If your goal is to kill people, take a look at the Colorado movie theatre shooting. He started with a shotgun and then switched to a rifle. Most of the deaths were caused by the shotgun even though he shot many more shots with the rifle. So maybe we should ban shotguns because they are much deadlier!
The stupid thing about these laws is the rather arbitrary method in which they mark some guns as 'OK' and some guns as 'not OK'. For instance, most assault weapon bans put an AK on the bad list, but the SKS* would still be legal. Automatic AK's would already be covered under machine gun regulations, so let's compare the semi-auto version with the SKS. They fire the same round, the SKS is generally slightly more accurate, well practiced gunmen can fire 100 rounds out of either gun in about the same length of time, but the AK has a removable magazine and a pistol grip while the SKS has a fixed magazine and no pistol grip so the AK gets banned but not the SKS, all based on cosmetics. The same thing happens with the AR and the Ruger mini-14, the mini-14 looks nicer so it is allowed, even though it has the exact same functionality.
* For this discussion I am considering the factory configuration of most SKS versions; you can buy an aftermarket stock with a pistol grip and swap the fixed mag for a removable one which would put the rifle under the same category as the AK.