For those worried about the LHC blowing up Earth, note that
the center of the Milky Way galaxy has a natural particle
accelerator that has been running for billions of years with
energies WAY above the LHC (try 100 trillion electrovolts)
and so far we're all still here.

See this:

http://www.centauri-dreams.org/?p=1087

And note that many if not most galaxies also have black
holes at their cores, many of them billions of times more
massive than the MWG's measly 4 million solar mass black
hole, and the terrors of the LHC shrink even more into the
realm of absurdity.

And I am surprised that this fact hasn't generated more
publicity, to say nothing of even more ignorant fears:

http://blogs.computerworld.com/lhc_compute_grid_will_say_42

If you are going to start quoting AIs from SF, give HAL a
rest and go with Colossus from The Forbin Project, an
excellent and deeply underappreciated SF film from 1970,
mainly because the AI never makes a stupid mistake and
is always 50 steps ahead of the humans - and ironically,
it is all because Colossus is doing precisely what its makers
asked it to do, stop nuclear war.