There's something akin to burying one's head in the sand about this approach. Implying YouTube has no reason whatsoever to examine itself. The actions of psychopaths can be like canaries. You can say there's no relationship between YouTube and the shooter's actions, but I think that's a bad idea. I believe the drastic rise in mass shootings is itself symptomatic of something. Something that is being drowned out by all the yelling about guns. Why so much rage in a supposedly civilized and wealthy society?