How are pirates still around?

What I don't get is how pirates are still alive and well in parts of the world.  Just today Somali pirates seized 4 ships, just days after having 3 of their pirates killed in a hostage situation.  In my  mind, our government should work with other nations to put a stop to this pirate pillaging.  Pirates were made to be 'cool' growing up, but there is nothing childish about these pirates: they steal, take hostages, and even kill.