Since when did it become bad practice to arm merchant ships and their crews? "Pirates are generally armed with assault rifles and, increasingly, rocket-propelled grenade launchers. Modern ships' crews are usually unarmed for a number of reasons, among them laws that prevent armed vessels from docking in the ports of many countries."
What silliness. The ONLY way to stop piracy is to stop and KILL enough pirates until the remaining would-be pirates believe they have more to lose than to gain by attempting piracy.