What to do about Pirates?

I have been giving some thought as what to do about the Pirates who have boarded the Yacht of 4 Americans off Yemen and kidnapped them and are heading southwest to Somalia. There aren't many options even though our military knows where they are and are tracking them and wanting to stop them form taking the Americans on shore in Somalia for fear they will never been heard of again. So what would you do about this and what do we do to stop the Pirates from boarding and stealing ships for ransom?

The question is this, even if we took the most aggressive action and boarded the yacht and killed all of them and possibly lost the 4 Americans, I am not sure it would deter anyone from trying it again. It is a real problem. How about some suggestions from you?