I often see this targeted specifically towards law enforcement drones. But what about MY drones? Facial recognition software isn't limited to them, and camera-toting low flying drones (or just cameras) are increasingly lower in price. (Example, the AR.Drone.)
If laws are needed to protect privacy, they need to be expanded beyond just law enforcement. I'm certain that Facebook, Amazon, Target, Google, etc, all have far more extensive databases that can (in conjunction with facial recognition software and a camera) not only track where you are (and verify with cell phone data) but what stores are between your destinations, in your vicinity, and target advertisements very specifically.
The government is not efficient enough, nor do they have the technical savvy, to use the vast majority of the data they collect. Even assuming that department A talks to agency C, or that they have remotely compatable databases/protocols.