If you hit someone with a frying pan it's considered assault with a deadly weapon so it's not considered 'safe' just stationary without direct attention. You basically have to have to attack someone for frying pan's or Pencils to hurt someone, where all it takes is intention or any number of mechanical / software failures to cause harm with a drone which is a vary different situation. It's the difference between a car and a gun and you need a licence to drive a car on the public roads.