Over 50 churches in France vandalized, desecrated or burnt since February. Statues of Jesus, Mary, the Apostles and Angels decapitated. Crosses pulled down, broken to pieces.
Decapitation is a theme. "He ('Issa') will break all the crosses" is a theme.
Of a particular movement, I've heard.
I concur with livius and furthermore, once it's established accellerants were used, that's "the how" - then it'll be on to "the who!"
Muslims were stupidly hired to work on the renovation!