Only parents and children can use child and parent parking bays

I see on a daily basis and miss out on parent and child parking bays to people who don't have children with them. They fail to understand that parking in normal bays with small children is dangerous as cars can swing into bays without knowing what our who could be in the bay and potentially run children over. Also, people can park too close to cars and parents are unable to place their children into seats from the door.