Just like many other answers in this FAQ section, this one also depends on a variety of factors. Most importantly, it depends on the type, size, and weight of the drone in question, and the use case. For instance, if we’re talking about small, lightweight drones for kids, they can be operated by anyone. If, however, we are talking about expensive, sophisticated, commercial platforms, meant for commercial/industrial tasks, they can only be operated by FAA licensed pilots.