CCTV camera in school toilet?

I came across this webpage which states that the school was forced to remove CCTV cameras from school toilets. I don't understand why the headmaster approved such installation. From what I have gathered, the headmaster had no knowledge of it. Well, I am glad that those CCTV cameras are going to be removed before students go to loo during schooling hours.

The question is why have they done so? I don't understand. It is a matter of invasion of privacy. That is pretty ugly from my point of view. I really hope that everything will be alright over there in Devon. That is pretty bad. Oh no...