Uh, I think his/her post was intended to be sarcastic.  Sad thing is, there's actually truth in it.  The U.S. culture accepts killing a lot more than many.  People in the U.S. rarely talk about the murders in their big city seemingly every day.  Huge attacks like this will be mainstream talk for about 2 weeks, then it'll fade into nothing.  Nobody talks about the tens-hundreds of thousands we kill in the middle east.  Americans are more numb to killing than many Americans realize, comparatively speaking to advanced nations.