The bottom line is, that it is an Experiment. Experiments by their very nature have predictable AND un-predictable results. Governments and scientific organizations have been suing each other for years arguing about its safety. The problem here? Black holes. Tiny ones that are expected to disappear instantly, or fall off into space for others to deal with - or - suck up the whole universe. It is definitely beyond my ability to assess whether I should worry. Skeptical scientists used to worry that people would explode in fast moving trains. And yes, trains have exploded but not because of science, but because of religion and politics - when motivations of power and greed were combined with fast moving trains. There-in lies the danger.
We used to think that we were the center of the universe, with the sun orbiting our enormous world, and the sky surrounding us with millions of little lights to make things sparkle. Suddenly we were just one planet of many, in a mediocre solar system. Then even our solar system was just a tiny spec of dust in a gigantic galaxy, and after that even our galaxy turned out to be nothing much among a sea of far more gigantic galaxies. Now superstring theory is talking about infinite universes, so even our universe is no big deal. If we take this to its logical conclusion - we don't exist at all. This final leap into this paradoxical realization may be the hardest one to accept. Of course it is possible that in higher physics circles they already know this, the same way this is known to the enlightened ones.
There is the chance that through this kind of experiment at the LHC, our non-existence will become clear or at least something to consider and build into the physics equations, as well as into our religious understanding. The annihilation of the universe may indeed turn out to be the result of this experiment - not literally, but in our understanding of things - or better - our realization of Nothing, meaning our infinite and eternal existence outside the realm of time and space.
May we have the required humility and grace to handle such knowledge.