Boy, 15, Killed in Bed by Stray Bullet in New Jersey -

It's very sad when things like this happen.

That said, you cannot blame the gun for an accident like this. It's just a hunk of metal and wood. The article calls the gun a "military style semiautomatic rifle." Please keep in mind that military rifles use exactly the same ammunition as hunting rifles. The fact that the gun is painted black doesn't make it more deadly. You can buy semi-automatic hunting rifles (while the magazine is usually smaller, the function is basically exactly the same.) Almost any rifle round is capable of piercing some amount of concrete.
This tragedy was caused by the negligence of the OWNER, not the scary "military gun."

Also, for something like this to happen, you have to violate every gun safety rule. He bought his gun on the street and probably didn't know a damn thing about how to use it.

I teach the gun safety rules just about every chance I get, in the hope that it'll come in handy if someone who doesn't know how to use a gun ever runs into one. So, here are the rules (as I teach them, anyway. Different people teach them differently.):
#1 - Never place your finger on the trigger - or in the trigger guard - unless you're ready to shoot.

#2 - Always assume the gun is loaded.
When you pick up a gun, check to see if its loaded. Then check it again.
Any gun you haven't personally unloaded should be treated as if it were loaded.

#3 - Never allow the gun to point at anything you're not willing to destroy,
Always know that if the gun were to fire at any moment, that it would not destroy anything you'd miss. This rule still applies to unloaded firearms Even if a gun is unloaded, you don't point it at people, pets, anything you don't want a hole to be in a millisecond from now. Sure, I do dry-fire exercises at the TV. I need a new TV anyway. :P
Which leads us to rule #4...

#4 - Always be aware of your target, and what's beyond it. I can do dry-fire exercises at my TV because I know that because I have a basement apartment behind the TV is a brick wall, and immediately beyond that is several tons of dirt. I never allow a firearm to point upwards towards other people's apartments until I've triple-checked that it's unloaded, and field-stripped it to the point that it is mechanically incapable of firing. When I load and unload, I aim at the tv with that nice brick wall and tons of dirt backstop.

Rule #1 and 2 guarantee that you'll never fire a gun accidentally, Rule 3 and 4 guarantee that if you do, in fact, manage to fire the gun accidentally, you'll never harm anything important. If everyone followed the rules, tragedies like this simply wouldn't happen.

So, he broke the rules. He put his finger on the trigger while "fiddling around" with his gun. When he did so, he didn't bother to insure the gun was unloaded. When you combine those two, you have a possibility for the gun to go off. He didn't pay attention to where he was pointing it, or much more important in this case, what was beyond it. And when you combine those two, you have the possibility that someone you don't intent to harm, will be harmed.

So, which do you think is more achievable? Getting every gun off the street, or teaching everyone how to ensure a negligent discharge will harm anyone?