UPDATE: I am getting plenty of email and chatter with the following argument: From an article at BLACKFIVE
I just finished listening to the press conference w/ ADM Gortney about the rescue of Captain Phillips. At the time it happened the USS Bainbridge was towing the lifeboat to calmer waters as the sea state was deteriorating. One of the pirates was on board the Bainbridge as the talks about obtaining Phillip's release continued. The lifeboat was approx. 25 m behind the Bainbridge when snipers on the fantail observed one of the pirates in the pilot house of the lifeboat pointing an AK-47 at the back of a tied up Phillips and the other two pirates on board were visible (at least shoulders and heads). The standing authority gave them clearance to engage the pirates if the life of the captain was in imminent danger. The on scene commander deemed this to be true and gave the order to fire. All three bad guys were taken out and then a rigid inflatable boat went to the lifeboat to retrieve Phillips. Iti is unknown at this point whether the shooters were SEALs or Marine Scout Snipers as both would have been available. This was not a rescue attempt ordered by National Command Authority i.e. the President. It was a reaction by the on scene commander under standard authority to safeguard the life of a hostage.
READ THE WHOLE STORY AT BLACKFIVE