This is probably the thing that will change the world more profoundly and shockingly than almost anything else over the next 5 years.
That's about the time it took smartphones to become ubiquitous in the developed world, and for business and culture to re-organize themselves around them. (If you're conservative, you can assume it took 10 years.)
Now imagine that nano-quadcopters (with video surveillance) hit hundreds of millions of cheap units in the next 5-10 years. What happens when everyone from concerned parents to nosy teenagers, criminals to police to political protestors have them. What happens when they routinely monitor traffic in the streets? Routinely carry out inspections of industrial infrastructure? Routinely patrol your house when you're out? When they're a standard tool of industrial espionage and gutter journalism? Where they guide automated cranes and architectural scale printers in docks and on construction sites? Where they monitor pollution and conduct ecological surveys in forests?
Nano-quadcopters and sousveillance are coming. And the world is going to be unimaginable.