What you said is partially true.... All these terrorist organisations do not commit the acts of terrorism to save Hinduism or are motivated to their evil acts guided by the teachings of a particular book. Infact most of the organisations which you quoted are least bothered about Hinduism....leave alone dying for it. They have a different ideology ad it is nothing connected with religion. It will be wrong to call them as Hindu terrosists unlike those folks of Al Qaeda, Jaish and other outfits who die in the name of Islam.
