Stronger gun control laws? Of course.
Should we ban firearms? I don't know about an all-out ban, but MUCH stricter control on rifles. I don't think the average citizen should have firearms. There should be a better reason than "I want one" in order to be granted a license. And yes, ban all handguns except for law enforcement.
Whose fault? Well, sometimes the parents contribute, but generally I think that these people are simply f*cked up in the head.
Are they desensitized to violence because of movies/video games/music? Probably, but not to the point that would make them do this. This incident was a result of mental illness, IMO.
Relax... I'll need some information first. Just the basic facts - can you show me where it hurts?