The whole trend is just too sick for words, I can't remotely imagine how someone could do that... it's a total nightmare. I find it scary in a different way from terrorism originating from / based on ideologies from far-away places, because it seems like these perpetrators come from right amongst our own society, even if they are outcasts. As said above, it's like a total FU to society, a total breaking of the intangible bonds holding us together. That seems to me to be terrorism of the worst type. And I'm not sure how these incidents can ultimately be effectively prevented, because it seems to me that living in a relatively free society correlates with the ability to do something terrible like that if you are completely determined to do so (i.e. if you don't care about either common morality or the deterrents we have in place). Politicians in Canada talk about gun control but I doubt the real effectiveness of those measures against sick criminals. I have no idea what (acceptable) solution could be effective against people who have stooped to these levels of criminality.
Something I've wondered is whether these types of incidents are a new thing, or whether they're consistent aberisms in society. Are there more people that feel extremely isolated and bitter against society (if that is the reason people do this), and even if so, what drives some of these people to commit violence? Is the fact that these crimes have been perpetrated against schoolchildren unknown to the criminal the only new trend? If so, what's the cause - is it just copycatting?
I really feel like we need to figure out why the hell this happens and how we can stop it.