Boko Haram is just a name and the members are just appendages. It's the sentiment and ideology that's actually the actor. Once that's understood, it becomes easy to understand why radical Islam extremism has occurred, does occur and more importantly, how to adequately address it.
It's a matter of what's in the skull. Ideological warfare is the apex of all warfare. Refugee programs aren't the Trojan horse; the refugees are. What's happening with groups like Boko Haram and ISIS(which are one in the same now) are actual, physical and tangible, manifestations of the thought.
People need to understand that.