I find it odd that there is a rap, but I'm glad that the video has lead to a discussion of science in general.
For about two and a half years, I was working with simulation data from the LHC at FermiLab and by remotely accessing their computers from my university. It was quite interesting for the first year and a half or so, but later turned into a big software/bugtesting project and I subsquently gave up the work. (I'll not go into details about that because that would be in extremely poor taste.) But as a result, I know a fair bit about the accelerators at Fermi and CERN, as well as how the scientists work and what they are looking for.
I feel it is worth mentioning that black holes do form inside the accelerators, but since black holes are so widely misunderstood, this fact has aroused some concert. Black holes decay at a rate which is dependent on their mass; I don't have the equation on hand, otherwise I'd be happy to post it. As a result, the black holes that are created in the accelerators pose absolutely no threat to anybody. It is also worth mentioning that black holes are formed in out atmosphere by high energy particles colliding with the atmosphere, though those black holes don't seem to receive much press. Examining particles created from high energy collisions in the atmosphere was a precursor to man-made accelerators, and a number of useful experiments can still be performed with such observations. Not that I would consider it useful, but in an advanced laboratory course I took, one of the available experiments involved measuring the lifetime of the muons created by cosmic rays.
I would also like to add in that there have been quite a few spin-off technologies that have been developed from accelerators, most notably the microwave. There is also an area at FermiLab that treats cancer with neutrons.
Oh, one other thing; there are highly active (radioactive, that is) areas around any non-linear accelerator (I would say all accelerators, but I'm only certain about non-linear ones). The main area is where they "dump" the "beam" in case anything should go wrong. The beam is what the stream of particles going around inside the accelerator is called. Dumping is exactly what it sounds like; the beam is forced out of it's normal path and into the ground in a gives spot. An example of something that could go wrong: the beam somehow moves out of it's intended path and begins to run into any of the various things just outside its path (there are tons of electronics, magnets, cooling elements etc). If you think one bad stroke on a hone is bad, imagine a stream of particles upwards of 99% of the speed of the light even just grazing any material.
Oh, one more thing. Now that I've started watching the "rap," it's nice to see that my work is referenced, though I don't really want to say what it was, due to the above bit about bug-testing.
