it doesn't sound very efficient, but a market-based national defense nevertheless:
Somali piracy has its roots in the 1990s, when the collapse of the Somali government threw open the doors to major foreign fishing companies to illegally enter Somali waters and fish out all the tuna, which once comprised one of Somalia’s major commodities. The first Somali pirates were fishermen who decided to render a "fine" on any boats they found illegaly fishing Somali waters.