Jules Verne's 'Leyden ball' gun - being built today

...the balls sent by this gun are not ordinary balls, but little cases of glass. These glass cases are covered with a case of steel, and weighted with a pellet of lead; they are real Leyden bottles, into which the electricity is forced to a very high tension. With the slightest shock they are discharged, and the animal, however strong it may be, falls dead.     - Jules Verne (1875) 20,000 Leagues Under the Sea

Turns out the Department of Homeland Security wants some:

Mide Technology Corporation of Medford, Massachusetts is working on a non-lethal device called the Piezer (pronounced "pee-AY-zer"). [...] The Piezer contains piezoelectric crystals, which produce a voltage when they are compressed. The Piezer is designed to be fired from a standard 12-gauge shotgun. Mide claims the Piezer could be effective at 40 to 50 meters, longer than the 'bean bag' rounds also dispensed with shotguns.