Just one minor point for those thinking a couple of destroyers should be sent to blow Somali pirates out of the water on sight and it'll be all over in two weeks.
The Somali coast line is very, very long, mainly cos the country turns a right angle. Pirates have been operating up to 500 miles from their own coast. That's a hell of a lot of water to patrol. On radar a pirate vessel looks exactly the same as any other vessel (and it's a busy shipping area) so you'd need visual confirmation on every suspected target.
And when you get visual confirmation how do you tell a peaceful Somali fishing boat from a pirate Somali fishing boat? Can't just board and see if they're armed, all Somali's are armed, peaceful or not. The only way to be sure a vessel is committing piracy is wait for it to attack something. Trouble then is you still can't just blow the boat appart cos they'll have taken hostages.
And as for hitting them at their bases.....see earlier point about coastline length and try to imagine just how many little coastal settlements there are up and down the Somali coast and then try to imagine just how many armed (and slightly insane) Somali's there are hanging around them.
And then go watch Blackhawk Down.