I agree with much of what you are saying in the post above.
I do think it is odd that more young people are committing these kind of horrific acts.
However, before the internet existed, people like Ted Bundy and Dahmer, Charles Xng, etc. were performing similar atrocities. I would like to see some honest statistical research(ha ha good one I know...), or at least analysis without an agenda, to demonstrate the full spectrum of these incidents. If we could see that the numbers may be dropping, but the criminals are in a much different age bracket, that would be helpful information.
I happen to believe that one of the major problems in our society which contributes to the swelling numbers of kids who are interested in this violent material, is the sexually repressed environment we live in. Yes, the United States, on the surface a country in which sexual metaphor can be found in all kinds of advertising (including hamburgers), is sexually repressed.
All day long, violence of one sort or another is replayed on news programs. At the same time, Janet Jackson's exposed nipple is cause for public outcry, huge fines, the involvement of the Supreme Court, and congressional hearings. The fact that the simple exposure of a woman's nipple created so many problems is ridiculous. It is a breast. Babies often nurse on breasts. Men can show off their tatas in public, so why is a little extra fatty tissue a big deal? If I was from a foreign country and I heard about this incident, I would immediately think the U.S. lived under the guidance of some very puritanical rules.
My point is that those things which are not given a natural comfortable place in society, will take root in the underbelly of society and become more seductive due to the repressed nature of the topic.
Sorry to ramble, I just feel as though the healthiest and quickest way to change this obsession is to stop making the human body such a big deal. It is just too confusing to be constantly bombarded with things of a sexual nature, or innuendo, but not have the comfort level to discuss them openly with people.