Messing with things we don't fully understand

For the first ever man initiated nuclear explosion, the Trinity Test, betting pools were set up for the results of the test. According to Wiki, Some predictions ranged from zero, a dud, to 18 kilotons of TNT (predicted by I. I. Rabi), to destruction of the state of New Mexico, to ignition of the atmosphere and incineration of the planet (fortunately, this result was calculated to be almost impossible beforehand, though for a while it caused some of the scientists some anxiety). As it turned out, Rabi won the bet.

Strikes me as being extremely foolish risk and and it was rather fortunate (or maybe not, I've never been to New Mexico) that it wasn't as catastrophic as some of the predictions.

Which brings me to my point. The Large Hadron Collider (LHC) currently being built at CERN will be able to smash protons together at ridiculously high speeds. There have been a number of safety concerns. Again according to Wiki, these concerns are:

Creation of a stable black hole
Creation of strange matter that is more stable than ordinary matter
Creation of magnetic monopoles that could catalyze proton decay
Triggering a transition into a different quantum mechanical vacuum

CERN performed a study to investigate whether such dangerous events as micro black holes, strangelets, or magnetic monopoles could occur. The report concluded, "We find no basis for any conceivable threat."
All the evidence points against but as one of the leading researchers said, "it is astonishingly unlikely that there is any risk - but I could not prove it."

Still makes me a little nervy but I know that is because I have a paranoia that borders on psychosis. So let the research go on! I think the faint chance of annihilation is a small price to pay for the knowledge of the nature of our Universe that this will engender!