Every time I hear that kind of a story, I wonder if I should come back from UK to my home country when I need to send my kids to school; just so they can go to a normal place. Sure - it may be a less known school. But at least you get treated in a normal way and the rules are not that different between the school and any public place (i.e. you'd have to have a knife in your hand to get stopped). I can't imagine any teacher there asking me about any electronic equipment to be honest... (apart from genuine interest, or in a "do you really want to bring that to school - for your own safety" way)