Last Friday the Portuguese frigate Corte Real (not be be confused with the ex-USS McCoy Reynolds, which had the same name when it was in Portuguese service) was called to the aid of an oil tanker being attacked by Somali pirates. After foiling the attack, which probably took no more than one burst of their Oerlikon 20mm auto-cannon, they launched a helicopter which followed the small boats back to the mother ship, a fishing boat. The mother ship was boarded and 19 pirates were captured.
These photos from NATO show the weapons captured (click to expand).
Just the kind of weapons you would expect the pirates to be carrying. Rust prevention does not appear to be a major concern. I would hate to see what condition the bores are in!
Soon after the capture the pirates were released on shore. Under international law pirates can be prosecuted in any country. Unfortunately a “live fire” training opportunity is one thing, but few countries or politician want the expense of pirate filled prisions.