Gun Control

I'm wondering about something: The second amendment guarantees us the right to keep and bear arms, including semiautomatic weapons, a vast majority of which end up in the hands of those who shouldn't have them, but marijuana is illegal?

The reason I bring this up is because yesterday an 8-year-old from Connecticut accidentally shot himself, with his father standing right beside him at a gun fair in Massachusetts.
(See story: http://www.courant.com/community/news/ec/hc-ap-gunaccident-1027,0,7933566.story)

I fail to understand how "productive" ways of guns ownership (hunting, self defense?) can outweigh the problems associated with guns.

Just tonight on NBC Nightly News, it was reported that, in this horrible economy, gun sales were up 10 percent in the last few months. Brian Williams didn't have a very good explanation for why this is true during the broadcast, saying that perhaps people are taking money out of their banks and keeping it at home, so they need a gun to protect them. Is a knife or baseball bat not good enough? Are people that paranoid about getting robbed?

And then we have video of Sarah Palin taking target practice, showing off her ability to shoot a handgun and people are getting excited about this?

If it were up to me, police, armored truck drivers and DEP employees would carry guns. I just don't see why common people need them, or should have them.