I am not a lawyer nor am I a legal scholar, but, I think that the intent of the person flying a drone can be determined if he can be charged criminally even though he is flying within the FAA and other regulations.
As with the example of the 16 yo bikini clad girl and the hormonal 13 yo boy, if his intent is to capture pictures of her and distribute them, either for profit or just plain titillation, he may be in violation of a criminal act of stalking.
As with everything new, the novelty will wane and things will settle down, but, As BendOrLarry said, some folks just like to complain. They (drones) are here to stay so it is best to relax and accept them. Baring illegal activity.