Only against non-muslims, as far as I've gathered. Most of the muslim world (as far as I've gathered) isn't particularly religious, just very socially conservat

Only against non-muslims, as far as I've gathered. Most of the muslim world (as far as I've gathered) isn't particularly religious, just very socially conservative. So IS isn't employing this tactic to its full advantage here. Nor is it clear how they could, because as long as you go through all the motions it's hard to check whether you really have all that much religious fervour.