Fear and the rhetoric of 'unprecedented' barbarity by Mark Durie

Many leaders have been stating that the Islamic State’s actions are ‘unprecedented’, ‘extreme’, ‘unique’, or even ‘eccentric’. ..

The actions of Islamic State’s adherents are morally repugnant in the extreme, but only by applying historical amnesia and selective vision could one claim that their evil is unique or unprecedented.

http://blog.markdurie.com/2014/09/fear-and-rhetoric-of-unprecedented.html