A non-profit think tank concerned with nanotechnology's potential for abuse recently issued a report. The results are pretty much what you'd expect from a bunch like that:

The Center for Responsible Nanotechnology, a non-profit think tank focused on studying the economic, security, military and environmental implications of nanotechology, has developed a series of scenarios dubbed "Nano Tomorrows." And one of those tomorrows involves the cheap and easy proliferation of "fabber," or "Easy-Bake," micro-UAVs with small explosives.

I'm more interested in a fab that'll let me make my own car, but I'm funny that way.