Kevin Black came across a bizarre paper recently suggesting that the LHC might be shut down. Not because of the funding cuts that have been threatening particle physics projects around the world, nor because of law suits accusing the LHC of threatening life on Earth.
No, the paper suggested that future effects caused by the production of particles, such as the Higgs, could ripple backwards in time and prevent the LHC from ever operating.
http://fqxi.org/community/forum/topic/230