Donkey's years ago I saw what must have been one of the last of the Liberty ships in Belize harbour sporting a Bofors like anti-aircraft gun on a raised foredeck. Piracy in the Caribbean was not unknown at the time so this was their answer.
I can forsee some Somali pirates highjacking a vessel. Sailing it down the Somali coast picking up hoards of extra passengers and then sailing it to Southampton. They would be met by an army of refugee groups and Legal Aid lawyers and in no time they would be set up in a house with free furniture, TV and lots of money to keep going with.