In movie: Nano-robot

About 2 months ago I watched a movie: G.I. Joe: The Rise of Cobra (in chinese: 特种部队：眼镜蛇的崛起). I was impressed by the weapon which crimes use to destroy Paris (exactly Eiffel Tower）in just 10 seconds (time in the movie). Which sci-fi weapon has this kind of power? Maybe it's nano-robot. These guys are self reproducible and if without any control, like after n times of self reproduction all guys will detroy themselves, they will soon ruin earth (not only the surface). Gezhi.org has an interesting article on "how to use nano-robot to destroy earth"(in chinese). It mentioned a movie at here ( http://www.mentalfloss.com/blogs/archives/23426 ). Watch it(from youtube)! It's amazing.

Below is a sci-fi snapshot of nano-robot by artist Adam Baines. Imaging this guy come into your brain, will it be OK?

http://www.321design.com.cn/blog/attachments/month_0912/i20091215111917.jpg