Question: What happens if a kid puts his finger in a personal drone propeller's workspace while its flying? Answer: The micro and mini drones such as the Hubsan Quads X4 and the Syma X1 have weak motors and relatively soft props, so injury more than a scratch or a cut would seem unlikely. When you start stepping up in size to so-called "brushless" motors which are much larger in size and may have hard carbon fiber propellers, there is definitely a danger. Some larger models, such as the Parrot AR Drone, stop the propellers as soon as they hit anything (including you!). Larger models often have to be "armed" while the pilot is at a slight distance - by using a two handed movement on the control sticks. This type of setup can help to avoid injury. In the end, though, quadcopters are certainly no more dangerous than the many hobbies and sports I participated in when young - model rockets, archery, rifles, etc. among them. Note - although your question mentions kids, I would guess that many more adults are being injured than younger folks. Also, most of the consumer quadcopters have a suggested age on the box or literature. 14+ and 18+ are two which I have seen, although it would be my opinion that supervised younger children could easily fly many models. After all, you can get a real pilots license at 17 and solo them at 16. As always, safety adherence and common sense need to be combined with training and experience.