article_snippet: It is estimated that 20,000 people have streamed into the territory in Iraq and Syria, where ISIS has proclaimed what ISIS calls a 'caliphate', ruled by ISIS often brutal version of Islamic law.
article_snippet: The group purport to recreate the conquests and rule of the Prophet Muhammad and his successors and maintains ISIS worst brutalities - such as beheading captives - only prove ISIS purity in following what ISIS contends is the prophet's example.
article_snippet: An ISIS member parades through the streets of Raqqa in Syria waving an Islamic State flag and brandishing a gun.
article_snippet: It is estimated that 20,000 people have streamed into the territory in Iraq and Syria, where ISIS has proclaimed what ISIS calls a 'caliphate' Many mainstream clerics compare the group to the Khawarij, an early sect that was so notorious for 'takfir,' or declaring other Muslims heretics for even simple sins, that ISIS was rejected by the faith.
highlights_snippet: ISIS purport to recreate conquests and rule of the Prophet Muhammad .
  
highlights_snippet: So far an estimated 20,000 people have joined a religious group in an estimated 20,000 people territory .
  
highlights_snippet: ISIS run a 'caliphate' under brutal conditions in parts of Iraq and Syria .