As Dr. Hawking once said,
if a black hole was created in one of these colliders, it would evaporate almost instantaneously, "and I would get a Nobel prize."
Really, this lawsuit is a perfect example of a little bit of knowledge being a dangerous thing. Black holes of the size which could be created are completely harmless (unless you happen to be standing within about a foot of where they're created, which makes you a candidate for gene pool chlorination). As for the 'strangelets,' the fundamental thing missing from the discussion is that even the LHC won't be coming anywhere close to the magnitude of energies produced by astronomical events, some of which send extraordinarily high energy particles into our atmosphere. The universe is a very big place - anything we're trying to do with the LHC has happened before somewhere, and the universe still exists.
These people should go back to complaining about superman costumes not having warning labels instructing children that the cape won't let them fly.