Nope. According to Reuters, defending against pirates only pisses them off:
Andrew Mwangura, coordinator of Mombasa-based East African Seafarers Assistance Program, said the rescue would change the stakes in future pirate attacks.
"This is a big wake-up to the pirates. It raises the stakes. Now they may be more violent, like the pirates of old," he said.
So far, pirates have generally treated hostages well, sometimes roasting goat meat for them and even passing phones round so they can call loved ones. The worst violence reported has been the occasional beating and no hostages are known to have been killed by pirates.
"This could escalate violence in this part of the world -- no question about it," said Gortney.
Well, I guess if thwarting their crimes is going to make them angry, we should just start a policy of giving a million dollars to every handful of yahoos who climb aboard a cargo ship. That surely won't have any incentive effects, right?