The Internet offers many locations to hide, and that is exactly what al Qaeda does. It hides behind other websites. For example, they might place their jihadi pages behind a web site that is for kids or about education. The subject matter that they hide behind doesn't matter. What's important to al Qaeda is that they constantly move their locations to keep authorities guessing. Al Qaeda uses common chat forums to inform their followers of their current web site locations, since they have more than one. The chat forums tell the jihadi followers which web site to visit to receive their messages. The web sites can have a number of messages from divine inspiration to what to blow up next.
Most spy agencies in the US, UK, and Israel are aware of this method, and they employ countless computer agents to track these jihadi forums and web sites. When the news media mentions that the spy agencies have picked up "chatter" from al Qaeda, they are talking about these jihadi forums and web sites. Al Qaeda doesn't rely too much on email, instant messaging, or texting because all these methods are easy to track. It's safe to say that the Internet is also the communication highway of al Qaeda.