0dungo knew about it and allowed the massacre to happen. They are Christians, so.. So WHAT, he says.
Yazidis are not Christians.
The Muslims have always accused them of being devil-worshipers, because they honor Melek Taus, the "Peacock Archangel" who is in charge of the Earth; however the Yazidis say Melek Taus is not evil and he is not Satan.
They are extremely culturally inward-looking, keep to themselves in every way, do not mix with others, accept no converts, and have never (to my knowledge) aggressed against anybody.
The Muslim fanatics say Allah wants to wipe them out.