Personally, I think the Navy should open up on them with a few salvos of 5" rounds, that might get their attention.
When we were anchored at certain ports over seas there were these little dingy boats that would come up and try and sell you anything and everything. They would also try to sneak on board and steal anything not welded down. Of course, we were not permitted to fire on them, however, we had fire hoses strung out on the bow and stern...and we sank many! ...needless to say we got some ugly responses from the thieves...words that even burned a sailor's ears.
-geo