While the benefits of nanotechnology are obvious to anyone with a loose understanding of science, I'm concerned that potential dangers will be ignored or dismissed by people who think they know better. Let's go forward 10 to 25 years and take these examples:

1) Criminals acquire the technology and can break any lock or security system.
2) Terrorists can selectively kill individuals or crowds from 1000's of miles away without bombs or guns.
3) Self-replicating abilities develop a fault and nanobots replicate uncontrollably.
4) Nanobots designed to break down pollutants or any other matter accidentally escape into the wild or develop a fault and can't stop this process.
5) True AI is developed and given to nanobots and they decide to alter the parameters of their programming and conclude that humans are unnecessary or require reprogramming. Many bad scenarios can develop from this highly complex situation.

While most of the above sounds far-fetched it's critical to remember that just over 100 years ago before man's first powered flight it was far-fetched to suggest that man would walk on the moon later that century, yet alone the notion that anyone can access nearly all of the information in the world from their own home and talk to anyone in the world. That's the Internet and satellite communications of course.

Politicians have a reputation for being short sighted and closed to unlikely sounding possibilities. Therefore it's important that they are convinced that the above scenarios are not totally impossible and extreme caution in guidelines and laws are put into place. Commercialisation is another factor that can put people in danger of uncontrolled or abused technology. GM crops are a good example where politicians and even some scientists with a commercial interest in it are playing down the dangers. The result is that GM is being forced on to the public right now. It's sneaked into our food and has been released into the wild. Even if a time traveller came back and told us that it will cause unimaginable problems, it's very difficult to undo the damage that has already been done.

Don't get me wrong, I'm excited by nanotechnology, but greed in the shape of commercial profiteering, backhanders and political motivation are the human dangers that can leave us unprotected from the extreme but not impossible horrors of nanotechnology.

Yours faithfully,
Gary Fenton
Woolmer Green, Hertfordshire
UK