How is a WiFi toy going to teach a kid anything about science? The whole thing is plug and play and probably not able to be modified or repaired. The helicopter could indeed be flown out of control range, or even more likely, be subject to jamming signals, accidental or intentional. In fact, it could probably be shot down with a rubber band from some of the "office marksmen" that I have observed in the past.
The concerns about invasion of privacy certainly do seem to be another consideration, unless the video resolution is so very poor that those observed are not identifiable.
I've recently viewed images from some people in Syria who have used something similar (although may have been homemade) to take birds eye photographs of demonstrations, which were then posted on the web.