The Mad Canuck's post this morning goes directly to a phenomenon that has plagued just about every faith: cults. Part of Christianity's social leverage derives from a discernment of cults, extreme spin-offs that present more a perversion than an expression of the faith. Without going into particulars, it is fair to admit that some cults have not only survived but become socially prominent. The same is true of other communities of faith, but I have yet to discover internal attempts, efforts by Muslims themselves, to examine their community to identify and marginalize cult activity.
Let's start calling a spade a spade, and a cult a cult. al-Qaeda is not an Islamic group, it is a dangerous and violent cult operating under the label of "Islam". And, while its members may profess to be Muslims, they have warped the teachings of their religion to the point it can be used to justify cold-blooded murder and do evil in God's name.
al-Qaeda, like some other dangerous cults, is a cancer. A malignant tumor growing within mainstream Islam, sapping Islam's resources, and denigrating the reputation of all Muslims by the evil acts it carries out in their names. Its members may start out as regular Muslims, but when they join the cult of al-Qaeda, they join the cancerous tumor, and start to act against the interest of the host (Islam).