Epileptic seizures. It seems that those really cool compact fluorecsent bulbs (soon to be compulsory in homes in the U.K.) tend to give off wavelengths that adversely affect the epileptic portion of our population. It's really not a problem though - the phenomenon apparently affects only a few thousand folks, and is a small price to pay for "saving the planet" from Global Warming. After all, it's probably not your problem.
Oh, but locked and loaded and ready to go: the next cyclic phase. Thirty years ago, it was all about Global Cooling. Then it became all about Global Warming. Oh, AlGore! You've just become so...cold. Will Compact fluorescents save us all from Global warming? Or will ordinary incandescents keep us warm?