We might be able to put a pin in this tech from a policy perspective, but the cat is way out of the bag as far as the tech goes. A cell phone already has all of the sensors you need baked right into it (honestly, we can thank mobile devices for getting the cost down). An ESC for a motor is a cheap microcontroller and a couple of MOSFETs. The frames can be made of cheap plastic. Even if things like ArduPilot didn't exist, a smart EE student could build one from scratch, including the flight control software, using parts from Digikey and relatively basic PID control code.
The cat is definitely out of the bag.