4chan and 8chan didn't create hyperirony (although they certainly cultivate massive gardens of it) or densensitization. Our media cycle has created it in tandem with a feedback loop that synergizes with the principle of "more people + same time amount = more hyperslices of emotion eliciting news that distort mental maps of larger-than-self situations"
You're safer at a wal-mart than prior 4chan and 8chan. But if you combine higher population density and information density, you'll get more raw events of violence even if the chance of experiencing violence has gone down.
Imo, there's a more insidious risk in allotting more powers of censorship to entities who are far less subject to reciprocal investigation. Think of 9/11. If we had done nothing, we would be safer and more prosperous today. We let the fleas provoke us into gouging untold amounts of flesh to stop itches.
Edit: A more simple way to phrase it is that hyperirony and the lack of "proper affect", which is really what people seem to be most horrified about, is a defense against the 24/7 atrocity exhibition which turns emotion into banality.
* - Note that more people, especially younger folks with their hyperbolic tendencies, and anonymity means more raw sociopathy and psychopathy being displayed in relation to those events. It's at least partially a function of the numbers game.