. >> ifill: for more, we turn to martin murphy, a visiting fellow at the corbett centre for maritime policy studies at kings college in london. he's also written two books about the horn of africa. welcome. how unusual was this series of events that we saw play out off the coast of somalia? >> well it is extraordinary. the somali pirates have generally been peaceable. their business model says we do not kill our hostages. it's extraordinary to see them killing four people in this frankly awful event. >> ifill: since we were last following this very closely which is to say the hijacking of the big ship, the alabama, had this faded away, gone away or did we stop paying attention? >> i think we stopped paying attention. there are many other issues around the world, somali piracy just rumbles on pretty consistently. it's only the high peaks, the mevg alabama, the hijack of a very large crew carrier or something like this, something tragic like this that brings attention back to what is a very serious problem. >> ifill: it's been going on. quantify how serious it is. >> we've now got over