Strategypage explains that the pirates already kill and harm their hostage crews. Call it 70 dead and 350 sometimes severely injured from various causes, including torture, over the last four years.
But we prefer the collateral damage of inaction. That's acceptable.
UPDATE: Putting security teams on ships could become ineffective in the face of new pirate tactics of swarming target ships:
Meanwhile, the pirates have improved their tactics on the high seas. Instead of single mother ships sneaking up on a large ship at night, and sending one or two speed boats after it, several mother ships are coordinating their movements so that a half dozen or more speed boats, each with four or more pirates aboard, can quickly surround the ship. Even if one or more of the speed boats are spotted, with so many closing in, and boarding at once, the pirates now have a chance of overwhelming any defense the ship has (including the increasingly popular armed security detachment of about four former soldiers or marines).
We're increasing the level of difficulty for the piracy, but as long as young armed men think that they can earn big money with high seas theft and live to spend it, they'll keep coming.
Until India leads a force ashore (because any European or American effort would be portrayed as imperialist, colonialist, and any other bad "ist" that can be conjured up) and razes every port used by pirates, ship security will need to be ramped up to include 20mm auto cannons or better with night vision sights to actually battle the pirates rather than just try to foil their boarding efforts. We'll be in East India Company territory then.
