There was no abberation of faith here. The hammer blows of secular law wont allow theists from killing people of other faiths or of no faith any more. Their violence is celebrated in the Christian bible.
Fundamentalist Islam’s celebration of the 911 attacks is the same celebration that the US had at the death of bin Laden (WWJD – was that turning the other cheek) or victories in Afghanistan or Iraq. It is the celebration of killing someone of a different faith. It is the denial of that person’s humanity.