Japanese troop ships returning to Japan often had Allied prisoners on board. That didn't stop the Fleet Boats of ComSubPac from sinking them. But of course that was then, and this is now.
I should have added, that we now have means and methods of taking such ships without sinking them. Travis is well aware of those means and methods. They aren't without risk of course, to both the hostages and the people doing the taking. Much larger risk to the pirates though.
Such as the Japanese ship carrying Australian POWs, that was fired on and sunk. The USS Pampanito (berthed, for now, in San Francisco) rescued them all and doubled the capacity of the already-crowded sub. Quite a story.
Our subs in the Pacific didn't know the "hell ships" were full of allied POWs when they torpedoed them.