Some say that banning "assault weapons" is akin to the "restriction" from yelling "fire" in a crowded theater. We already have such restrictions on firearms, knives, cars, and pretty much anything else. How so? Well, let's examine the statement.
First of all, I can think of a couple of circumstances in which it is perfectly acceptable to yell "fire" ina crowded theater. If there is a fire, you would be expected to warn others. If you are an actor, it may well be part of the play. We'll rule those out, though, and imagine you are a part of the crowd and there is no fire.
How do we keep people from yelling "fire," then? With punishments for the trouble caused. We haven't banned the word, as evidenced by the number of times I have used it in this post alone. If you misuse the word in order to cause a panic, you are punished for that.
We have laws against the misuse of anything potentially deadly. If I stab someone, run them over, or shoot them, there are penalties. Much like words, though, we shouldn't ban them due to potential misuse. Yes, guns can be used for evil, as can words, money, people, or anything else. We don't ban words, and we should not ban guns.