Is it possible to "electrify" parts of the hull and gunwales to deter piracy?

With the scourge of piracy off the coast of Somalia now costing billions of dollars in higher insurance costs, disrupted trade and ransom payments, something urgently has to be done. Is it feasible to modify the target ship's gunwales such that anything that tries to gain access to the ship's topside results in a nasty "zap"? What else can be done?