AJ, seriously, ISIS hates atheists probably more than they hate Christians. Don't be so foolish.
Atheists are just more in the "closet" in the middle east. If you told an ISIS member you did not believe in God, do you really think they would say, "Okay, we love atheists. Go along your merry way."
I assume either 1) atheists in the Middle East are keeping quiet about not believing in a God or 2) there is just a lot less atheism in the middle east when compared to America, Australia, and the UK.
They keep quiet because in some Islamic countries, atheists face discrimination and severe penalties such as the withdrawal of legal status or, in the case of apostasy, capital punishment.
Saudi ArabiaAtheism is prohibited in Saudi Arabia and can come with a death penalty if practiced.
In March 2014, the Saudi interior ministry issued a royal decree branding all atheists as terrorists, which defines terrorism as "calling for atheist thought in any form, or calling into question the fundamentals of the Islamic religion on which this country is based"
As for the West, A University of British Columbia study conducted in the
United States found that believers distrust atheists as much as they distrust rapists. The study also showed that atheists are unfairly discriminated against and as a result have lower employment prospects (because they are atheists)
BrazilA 2009 survey showed that atheists are the most hated demographic group in Brazil, among several other minorities polled, being almost on par with drug addicts. According to the research, 17% of the interviewees stated they feel either hate or repulsion for atheists, while 25% feel antipathy and 29% are indifferent.
These a just a couple of examples, for a more detailed explanation of the discrimination atheists still face across the globe, click this link.
http://en.wikipedia.org/wiki/Discrimination_against_atheists#Western_countries