From what I understand of the economics of Somali piracy, there is only one weakness to attack.

The financiers put up millions for the mother ships and the weapons. The worlds navies have to hurt their profits and make it too expensive to carry on the business.

Here is my plan. It is similar to the way that some us counties finance their police departments.

satellites and computers keep track of shipping in the affected area, suspicious ships are stopped and searched. If evidence of piracy is found the ship is sold for scrap with the proceeds going to pay for more searches.