Disgusting acts committed by radicals. The real question boils down to this though...in our world of picking and choosing which parts of a religion you deem worthy of representing, what do true fundamentalists represent?
It would seem in our modern society, it's easy to look at Islam and stereotype because amongst the violent religious sects, Islam is right in your face consistently, and it also brings with it a very vaguely understood set of practices to the western world.
A good example of radical Christian fundamentalists would be Westboro Baptist Church. They tend to be less violent, and more offensive...but the response is absolutely defined...they are considered outcasts, radicals and nut jobs. I like to think that the same can be said about the sects of the Islamic faith, and that people view them similarly...but over the years, I have seen some contrary attitudes from people who I would normally view as pretty "level headed" in terms of morality to your fellow man, regardless of religious belief. Instead of showing disdain towards such actions, they simply isolate themselves from such and say they would never do that...indicating to me that they don't necessarily see it as something "wrong", but as something they wouldn't or couldn't do independently.
But at the end of the day...there are radical groups in every religion. Even Buddhists, long considered to be the most peaceful of religious lifestyles, have their groups...
A Coordinated Extremist Buddhist Network Is Sowing Hatred Across Asia
Prejudice is a nasty thing...unfortunately there's plenty of fuel to perpetuate the action.