Is [Daesh](https://en.wikipedia.org/wiki/Islamic_State_of_Iraq_and_the_Levant) (also known as ISIS, ISIL, or Islamic State) predominantly Salafi? [This article](http://www.theguardian.com/world/2014/aug/16/isis-salafi-menace-jihadist-homeland-syria) says ISIS is Salafi, but I've come across someone disputing that.