The worst case scenerio to me would be an Earth Abides scenerio where a virus that kills nearly all of humanity is created. In addition to the book scenerio the terrorists would be based on the moon and after people suffer and grive, nuke the world into submission and eventually the terrorists on the moon would come down upon their holy site--Mecca, Jerusalem, Vatican--and then live life. If they were of a fundementalist and misogonystic kult they would forget to have women in their kult and quickly die out. The last three people in the kult will kill each other over a small squabble of docterine of the kult and the last person will commit suicide because he murdered the other two people. Maybe I should write a book...