I'll resist the impulse to make fun of the inbred, horse-faced Royal family here.
Even nanodaddy Eric Dressler thinks that nanotek presents certain dangers. He founded the Foresight Institute to explore mitigations to rogue nano development. (And to make money)

Obviously, each technical advance opens up new destructive opportunities for our species. Recent examples include computer hackers. Don't kill folks, at least not directly, but this illustrates the all to human propensity to do mischief.

Some appropriate awareness and caution is warranted regarding nano. Not that I'm worried about ever living to see archtypical "assemblers" run amok.