As endless articles have pointed out, before and especially after London, Al Qaeda has gone from being a centralized operation to a set of ideas and actions that are largely communicated via the internet:
Nearly four years later, al Qaeda has become the first guerrilla movement in history to migrate from physical space to cyberspace. With laptops and DVDs, in secret hideouts and at neighborhood Internet cafes, young code-writing jihadists have sought to replicate the training, communication, planning and preaching facilities they lost in Afghanistan with countless new locations on the Internet.
On one hand, this makes the movement much harder to deal with militarily. On the other hand, don’t we have a better shot at being effective in interrupting communications in cyberspace than when messages are being carried between caves on horseback?