Somali Pirates

Have you heard that Somali pirates attacked an Italian cruise ship? The liner had Israeli security forces aboard, who responded with fire, driving the attackers away.
Good for them.
And kudos to MSC Cruises– and any other company willing to take security into their own hands.
I mean, as much as I’d like to have a Marine attack copter dispatched to just blow a boat full of pirates out of the water at first sight, we really cannot expect coalition naval forces to be everywhere at once.
And pirating is lucrative to these people. More often than not, companies pay the ransoms for the safe return of their crews, ships and cargo and the pirates go back to their home ports, where they are hailed as heroes. Women flock to the ports to try to marry these guys, who are flush with cash and living like rock stars-- pirate style.
So what should be done? What deterrent would work?

I think we should model WWII merchant shipping. We had merchant ships sailing all over the world with all kind of war material—from supplies to troops to mail. These liberty ships sailed through all sort of harrowing ordeals, none more alarming than through the North Atlantic. German U-boats prowled, lying in wait for their targets to appear.
At first, the liberty ships sailed together with armed escort, but they soon realized that they presented an even larger target that way.
So they decided to arm the individual merchant vessels. They placed guns on the decks, covered and hidden from view and had Navy gunners there to operate them should the need arise.
That didn’t stop the German harassment altogether, but they certainly lost fewer vessels, and the merchant seamen aboard felt much safer.

Arming these present-day merchant ships would be the very best way to deter the pirates.

COOL UPDATE: 62 year old British passenger hailed a hero, throws deck chair at pirates.