Look at Post #8. Also this:
en.wikipedia.org/wiki/2011_Norway_attacks
And, of course, in Africa and the Middle East, it’s endemic.
I’m sure it’s a complicated thing. I, for one, have often wondered about the degree to which we “popularize” these attacks. I saw a psychiatrist comment that these kinds of things are often “celebrity killings”. Some disturbed person sees the celebrity awarded to some killer and, perhaps thinking his own sense of nonentity can be cured by even momentary “celebrity” does this. For goodness sake, remember the air-brushed photo of Tsarnaev on Time magazine?
I honestly wish these events were not made such a big deal of in the media.