I watched a documentary about this recently. A woman called the ambulance because her husband was having an epileptic seizure, but for some reason a policeman showed up first instead. Long story short, they tazed him to death because he would not 'cooperate' when asked to. The guy had no control of his behaviour and they just kept zapping him till his heart could not take it anymore. The companies making tasers all insist that they are non-lethal and that there have been no reported deaths due directly to the use of tasers, but that is total bullshit of course.