That's the thing with "evil". People try to make it into some kind of magical substance that only certain people have. It allows them to think "Oh, I would never do things like that. I'm not capable of it. I'm a good person. Only evil people do things like that, people who have evil inside them."
That is not what evil is. The root of evil is becoming so locked into your own personal beliefs about reality that you start seeing it as reality. You start thinking you have what's Absolutely Right and Absolutely True, so you then feel justified in harming or punishing other beings for being "wrong".
Watch the movie Downfall. It's about Hitler's last days in a bunker in Berlin. There was such discomfort in Germany about that movie, for many understandable and valid reasons, but one of the most interesting reasons was because no one wanted to admit that Hitler was actually a human being. It's much more comfortable to think he was a monster, completely insane, because that way we don't have to see the Hitler inside each of us. It's not that the film portrays him as a good person, just that it shows he was a person. A crazy, deluded person...but a person. And a person any of us can become if we too become totally convinced that we are RIGHT, and everyone else is WRONG, and dammit we will KILL THEM if they don't get with the program! That impulse is inside all of us, it's just a matter of how each of us address that emotion.
We all do this on one level or another (myself included), the West Boro Baptist Church is an extreme example of this type of behaviour, it also exists within the creation debate (or any opposing theologies for that matter) but is a softer example of this behaviour (if there is such a thing as softer when it comes to evil), even atheists are guilty of this behaviour (many want religion eradicated). It does not discriminate, it exists within all of us, we judge and condemn based on it and we think our own proverbial don't stink.
Anyway just something I thought I would throw out there.
Cheers