There are existing laws covering privacy issues and the use of cameras in our society, so we should be focused on ensuring those laws are adhered to by everyone.
The same concern arose when manned helicopters were first used by the police and news services, then when personal video recorders became popular, and again when mobile phones with their tiny built-in cameras became ubiquitous. All technology can be used for good or ill, it is up to the people using them to abide by the laws of our society.
And while it is possible to attach a camera to a drone and snoop over your neighbour’s fence, we believe this isn’t a serious concern because although they are much cheaper than the alternative of flying a full scale aircraft to see into private areas, drones are still high-tech specialized equipment costing thousands if not tens of thousands of dollars. It is unlikely that someone is going to spend that kind of money just to look through your bedroom window.