I seriously doubt Islamic extremists will resort to agro terrorism. Their acts are more of a sensational nature, intending to cause a sensation and deliver a message, rather than resort to agro terrorism which although deadly is rather a low-key affair and will virtually turn their supporters against them. Bombs and missiles and hatred will continue to be their weapons as of now. We should be investing more resources in making them fight amongst each other, rather than trying to protect ourselves from every possible imaginative form of threat.