As the Somali pirates have extended their range of operations, more and more merchant ships have begun carrying armed guards on board — even though many countries bar merchant ships from bringing firearms into their ports or territorial waters, and some forbid ships flying their flag from carrying armed guards:
None of this has stopped several private security companies from offering armed guards for ships. The security companies operate from countries that allow them (sometimes after payment of bribes) to have military grade weapons. The security teams sometimes travel unarmed to a port where they can pick up their weapons, and board the ship they are guarding. That works because some shipping companies are carrying rifles and machine-guns on board, but keeping them hidden from port and cargo inspectors. Large merchant ships have lots of places to hide things like a dozen rifles and pistols and a few thousands rounds of ammo.
Other security companies will send out a small ship with the armed men on board, and transfer them to the merchant ship in international waters.
In short, no one wants to talk openly about how this security business operates.
But until they are open, indeed celebratory, about carrying armed men, it will not have a strong deterrent effect on piracy.
Pirates need to know up front and unambiguously that they are likely to get killed, if we are return to safety on the seas.