Bad headline. They are not “extremists”; they are, as Al Qaida, ISIS/ISIL, HAMAS and Boko Haram, the true face of Islam. Convert, submit or die.
The command from the pagan god and his false prophet to kill the unbeliever
is repeated over in100 times in their unholy guidebook.
Unfortunately, love thy neighbor, do unto others, and forgive our debtors never modified or ended those commands.