It is all to easy to seek revenge as a response to such appalling events. But we have no right to judge others no matter what they may have done. Furthermore we can be sure that God will deal with the matter in His own good time.
I agree completely with Father Gregory, and feel he is absolutely correct in noting that we should respond with penitence and sorrow. I have to suggest that when we come across such events as the Egyptian persecutions of recent months, rather than calling down fire and brimstone we should reflect on St Paul who was converted from persecutor to champion of the Church. What better example could we have of how God works in such matters. I pray that God will show these people the error of their ways, and draw them to the infinite love of Jesus and His Church.
With love and prayers,