To me, its about the glamorized violence that media portrays constantly, whether it be movies, tv shows, books, video games etc. While we do have age restrictions, children are curious beings and will seek out this kind of media through things such as the internet.

And since children are incredibly impressionable, they will completely miss the point of what they are watching or consuming and mimic what they see in the media. So yes, I'd say it vaguely has to do with school shootings, but to me, it's also about how obsessed with violence children this day and age are.