I've become desensitized to the horrors of the world

These days, it seems like I can see some of the most horrible things in the world and yet not feel too emotional. I hear so many horrible stories on the news, on YouTube or any other site, yet when I see the stories, I usually have a straight face.

Whether it be rape/animal cruelty/pedophilia/torture/child abuse/murder/etc., my mind can typically handle the whole package. I've also seen people online posting videos of horrid things they did, and while this provokes mindless (though not necessarily unjustified) emotional rage from most people, I can calmly write a polite comment condemning the actions. I mean obviously I'd feel a little bad for the victims and may take measures to avoid it, but emotionally, it usually leaves little to no effect on me, and NO news story or raw footage of anything has left me in tears. Now before you accuse me of not having empathy, I do certainly understand the agony many of the victims have and are going through, and if I can I'll try to help. I just don't feel much out of those horror stories.

In this regard, I'm kind of like Sherlock from the new BBC drama. He obviously doesn't approve of the horrible things people do and will do many things to prevent it, but he feels little emotion when they happen.

Is it normal to be this way?

P.S. I am not saying that there is more bad than good in the world, nor am I a pessimist. I'm simply saying that I'm desensitized to horrible things I see.