This information is readily available for anyone who looks: http://www.nbcnewyork.com/news/national-international/Muslim-Scholars-Groups-Against-ISIS-Speal-Out-361309791.html
How Muslim Groups, Scholars Have Been Fighting ISISShortly after ISIS leader Abu Bakr al-Baghdadi declared himself leader of the so-called "Islamic State," Muslim scholars published a 17-page open letter to Baghdadi, challenging everything from his claim to be "caliph," or leader of the world’s 1.6 billion Muslims, to the way his group "cherry-picks" verses from the Koran to justify its actions.The September 2014 letter was translated into 10 languages and signed by more than 120 supporters, from the grand mufti of Egypt to a professor of Islamic studies at Massachusetts’ College of the Holy Cross.In it, the authors argue that Islam forbids forced conversions, slavery, torture, the killing of innocents and the disfiguring of the dead — all of which ISIS has notoriously done and sought to justify in its own extensive, multi-lingual arguments.Citing religious texts, the letter also says that Islam forbids the mistreatment "in any way" of Christians or "people of the book," and that it is "obligatory" to consider Yazidis — members of a religious minority that ISIS fighters have attacked and enslaved — as part of that group
This is the letter: http://www.lettertobaghdadi.com/14/english-v14.pdf It is signed by 126 Muslim leaders from all over the world and is the basis of anti-ISIS teaching in mosques around the world