I'm willing to bet none of these 20 year old maniacs have seen any of that. But I am also willing to bet they have all seen movies like Scarface and Dirty Harry in addition to all of today's violent movies.
Could part of the problem be that we used to root for the good guy with the gun on TV and in movies? It seems like the trend has been the last decade or so ago to make the villain the more compelling and glorified character.
Another thought.....
Is anyone familiar with paintball and Airsoft? I was checking this out, as I would bet that many parents just buy these "toys" without teaching proper firearms rules of safety. I would also bet that a lot of parents don't know these rules themselves. Now, my dad would never allow us something that shoots a projectile at anyone. I've was taught firearm saftey at 5 years old with a .22
Let's look at these "toys"...
Decent Paintball guns shoot at 320fps+, Airsoft Starts here and goes easily to 500fps+, both with high rates of fire.
The standard Daisy lever BB gun (Red Ryder) that kids should move UP to after playing with toys is only 280fps......very interesting.
The "toys" are sold with the intent on "shooting" other people. They are often handed out by parents who do not really understand what the "toy" is and why the rules of safe handling are just as important.
"Here kid, take this and get out of my hair. Go shoot some of your friends."
A possible problem is the lack of education and understanding of these types of "toys" and how they should be treated with more respect. Perhaps they should be used as tools to teach properly and never be used to fire at someone else. I believe I have crossed into the "de-sensitizing of violence" issue, but go check out the models of Airsoft available. I does make one wonder.