Make it illegal to take pictures of children and/or faces in public places

Me and my family went out Apex Park in Highbridge Somerset, I strange person took photos of my sister and other children with a camera and taking photos of children playing right up in there face, the police now have said that this is completely legal, How can a stranger taking photos of your child and/or children be legal? The law needs to change to take photos of children in public places, especially with children being bullied and harassed , let’s get this law changed to make this illegal!