Thank you for your comprehensive reply.
Let me relate to you a true event. In 2005 I was in the dep: lounge at Schipol airport. Everybody was behaving normally and a group of young lads were being 'loud', laddish I suppose, not misbehaving but a bit extrovert. A middle eastern looking man came in, spread a newspaper on the floor and facing East began to pray.
The atmosphere in the lounge changed abruptly. People went quiet, the laddish lads began look around and whisper. Everybody's eyes were upon this man and one could see fear in their eyes, thinking presumably what I was thinking,  "is he praying for a successful mission?" I remember saying to my wife, "If he's on this plane then we are not."
Airport security then brought a mobile security, x-ray station into the lounge and we all had to walk through it again. In the meantime, the praying man had disappeared altogether. We were assured our flight back to the U.K. was safe.
This is the reality, not the theory.