Soon ISIS wouldn't need any kind of help from other countries with passports and anything as I read that they are already in the process of establishing Caliphate. "Move that clearly is part of the terrorist group's symbolic creation of a caliphate, ISIS militants themselves reportedly started issuing their own international ISIS passports". I will tell you what their next step be from here: ISIS plans to expand beyond the Middle East to Europe!
Don't they have to be recognised as a country in order for their passports to be recognised?
They can all themselves what they want and all have nice Passports, they won't be getting into the US any time soon!
With a Turkish passport it might be possible, assuming they are unknown to the authorities.
I am surprised that Turkey helps ISIS so much, I understand my enemies enemy is my friend, but passports allow them to attack their real friends, which would have repercussions against Turkey.