A couple of days ago, I read about this weird thing in New Scientist : flicker illness. Apparently, if you flash a bright light at a person with a frequency between [sic] 2 and 60 Hz, said person may suffer from anything ranging from headaches and muscle spasms to violent epileptic seizures. Apparently, this was also the cause for people in Japan getting violent seizures from watching a Pokemon cartoon (not because the damn' thing was so awful, as was initially thought.)
Far-fetched as it might seem, I can't wait to head back to the elec lab, rig up an astable at around 30 Hz to a few ultra-white LEDs, and start flashing the damn' thing at anyone who stands in my way.