im with Boo all the way here - my eldest long left school and my youngest is in yr 2 but neither (hopefully) will ever have to go through scanners before their day starts.
What on earth would constitute an emergency that the parent would have to call a mobile phone?
Why does any child need a mobile in school? There are still these wonderful little things called landlines that, rather strangely, you can call from a mobile should the absolute need arise to contact John or Janet at school
Mind you, when you have parents who object to a simple pat down, the job of any teacher is going to be a hard one