I'm all for the advancement of science and technology, and maybe I've seen one too many science fiction movies, but if there was even a scintilla of a chance that we would blow our planet to bits by using this thing we wouldn't be doing it, right? Right!? :? Just making sure...
They've fired a test beam but have yet to create particle collisions. That is scheduled for October 31st.
I'm sure everything will be fine. It can create small black holes on earth, but those are harmless and will likely disappear instantaneously. I'm sure we're in good hands- science people tend to be smart. And stuff. :P