Teribus is absolutely correct. The only certain way to stop piracy is to eliminate the shore bases of the pirates. Without secure harbours to operate from, pirates are finished. So...you have to assault their harbours, sink all their boats, destroy their repairing and refueling facilities, and blockade or occupy those harbours from that point forward. Full military response, in other words. That's what was done to shut down piracy in the 17th and 18th centuries, and that's what would have to be done now.

There is apparently a lack of political will out there to do it. I wonder why that is? Can they just not be bothered? Do they consider it too politically risky or too expensive? Are the various nations all waiting for someone else to shoulder the burden? Or is someone profiting from simply maintaining the present situation as is?