only when you put a 9v battery to the sinus nerve in your heart will kill you. your body has a huge electrical resistance so only a few nanoamp/picoamp will cross your body. And moreover the most of the current will choose the fastest way across your body which is along the skin. and a battery is DC which is half as dangerous as AC. You should be very carefull with electricity but 9 volt is just not enough to make damage.
But I agree on the rest with you chilly.

capacitors charge up to the voltage you put on it. So if you put 120 volts on it and then onhook it, the voltage between the nodes is still 120 volts. people don't realize this and that is indeed very dangerous.