If true, where is the ACLU and why haven't the lawsuits been filed???

Hans Zeiger in the Oregon Magazine has an interesting column. Students in US public schools are given assignments to participate in Ramadan, pray to Allah and basically act like good Muslims for class credit. If a teacher or principal had students participate in Hanukah or Christmas (the religious side) and had the children chant Jewish or Christian prayers, the ACLU and other like minded groups would be launching lawsuits and protests to stop the practice.

Why are they not doing the same here? Why is one religion allowed to be taught in school and not another?