You'll find the ICC piracy reports here. They always make for interesting reading.

As they note:

The IMB Piracy Reporting Centre has received 31 actual and attempted attacks in 2007. Many more attacks may have gone unreported. Some pirates are dangerous and would fire their automatic weapons at ships to stop them. Occasionally, they would use their RPG (Rocket Propelled Grenade) launchers at ships. Pirates are believed to be using “mother vessels” to launch attacks at very far distance from coast. These “mother vessel” is able to proceed to very far out to sea to launch smaller boats to attack and hijack passing ships. Eastern and Northeastern coasts are high risk areas for attacks and hijackings. Vessels not making scheduled calls to ports in Somalia should keep as far away as possible from the Somali coast, ideally more than 200 nautical miles. Mariners are also advised to report any suspicious boats to the Centre.