Theory of relativity says it's impossible for the CERN to create a black-hole like this. I've heard somewhere that to create an actual black hole CERN would have be longer then we could fit on this planet and require more energy then we could ever produced.
Even if Einstein is wrong, Hawking's theories show a mini-black hole expels more radiation the smaller they are and would collapse upon itself immediately, posing no threat.
"The world will not come to an end when the LHC turns on. The LHC is absolutely safe. ... Collisions releasing greater energy occur millions of times a day in the earth's atmosphere and nothing terrible happens."
Prof. Steven Hawking, Lucasian Professor of Mathematics, Cambridge University
"Nature has already done this experiment. ... Cosmic rays have hit the moon with more energy and have not produced a black hole that has swallowed up the moon. The universe doesn't go around popping off huge black holes."
Prof. Edward Kolb, Astrophysicist, University of Chicago