cremeglace writes with this excerpt from ScienceNOW:
"You've heard the controversy. Particle physicists predict the world's new highest-energy atom smasher, the Large Hadron Collider (LHC) near Geneva, Switzerland, might create tiny black holes, which they say would be a fantastic discovery. Some doomsayers fear those black holes might gobble up the Earth — physicists say that's impossible — and have petitioned the United Nations to stop the $5.5 billion LHC. Curiously, though, nobody had ever shown that the prevailing theory of gravity, Einstein's theory of general relativity, actually predicts that a black hole can be made this way. Now a computer model shows conclusively for the first time that a particle collision really can make a black hole."
That said, they estimate the required energy for creating a black hole this way to be roughly "a quintillion times higher than the LHC's maximum"; though if one of the theories requiring compact extra dimensions is true, the energy could be lower.