fundamentalists and extremists

Many fundamentalists of all religions, including Wiccan ones (ones who use the word "Xtian" - I used to be like this.  We here much about the Islamic type, but some Wiccans and Witches cast dark spells on people.  Some commit poisoning.  Tim McVeigh was a Christian and I do not know his motive for blowing up the Oklahoma federal building.  We hear much on the news about terrorism in the mideast.  There are even Atheist fundamentalists.