Did you hear the one about the 2012 Olympics and Slaanesh? It would seem that Slaanesh has loaned some sonic weapons to the organizers. Or perhaps in the pursuit of perfection, the Emperor's Children have decided that they're going to show Terra how good they are at, ...well, everything.
Pet theories not withstanding, it was this BBC online article that caught my eye. It concerns how "sonic weaponry" is being deployed in London for security and announcements during the 2012 Olympics.