Right. So anyway...

The "doomsday scenarios" that people mention in reference to the Relativistic Heavy Ion Collider (RHIC) are indeed 1) black hole creation as well as 2) strangelet production causing the universe to leave a supposed metastable ground state for the true vacuum. Both of these scenarios have been addressed scientifically and shown to be impossible* in

Jaffe, Busza, Sandweiss, and Wilczek, Reviews of Modern Physics v.72, pp.1125-1140 (2000), http://arXiv.org/abs/hep-ph/9910333
In addition to sophisticated arguments, they use arguments like: a) the moon is being constantly bombarded by high energy cosmic rays and has been for millions of years b) the moon hasn't been eaten by a black hole or turned into stranglet soup c) the collisions at RHIC are of lower energy than the cosmic rays; ergo d) it'll all be okay.

*Using a reasonable definition of "impossible".