My point isn't whether or not IS exercises control over a group of people, but that the geography is vast and lacks security or rule of law by any party. In that sense, it is ungoverned.
Looks as much like a government as the one we support in Afghanistan. Stands to reason. ISIS may not govern their territory like a first word country, but they aren't a first world country. ISIS has only been in the governing business for several months. Ultimately they want a true calaphite. They want empire. It is clear they intend to govern under the law as they see it.
http://www.cnn.com/2014/09/18/world/meast/isis-syria-iraq-hierarchy/
http://time.com/3720063/isis-government-raqqa-mosul/