This online article from Popular Science discusses the safety issues many people have with nano-science as it has been developing.
Personally, I think that much of the controversy has been needless posturing. Yes, there are some realistic possibilities of dangers that do need to be accounted for, but we are not talking about technologies that are going to rob children, assault grandparents, and generally destroy the world as we know it.
If you couldn't guess, I don't buy into "Gray Goo" theories.
Actually, something that was interesting in their most recent issue was an article about new "nano-medicines," along with a short summary of some upcoming medical innovations. One that people want to see happen is a device, currently used on dogs, that is implanted in the host and releases controlled amounts of drugs. The release, apparently, is controlled by remote signal.
This seems like a bad idea to me. As one of my recent posts should remind you, there's always the potential for disaster with remotely controlled devices. The security on these things would have to be top-notch. I'm sure it's possible, though I must admit my knowledge of such matters is far too limited.
But imagine this scenario: Important Political Figure A has one of these devices installed. Assassin/Hacker B, miles and miles away, sends a signal to the device in A that suddenly releases a year's supply of meds into his blood stream. Most likely, the result is instant death.
Far fetched, yes, but something worth considering if such a device becomes available. I suppose with medical tech, it doesn't always pay to be an early adopter.