Cell phones are turning out to be a major terrorist vulnerability. When Saddam ruled Iraq, he did not allow a cell phone system to be installed, fearing that these devices would assist his enemies. In the last few years, cell phone service has flooded Iraq, and there are now over four million users. While cell phones have been used to detonate IEDs, the terrorists have found much cheaper substitutes (door openers, remote control toys, etc) for that task. The terrorists and anti-government forces find the cell phones much more useful for communication. Especially for Iraqi terrorists, cell phones were like a new toy, and users quickly became addicted. That turned out to be a mistake. The United States has lots of equipment that can do lots of stuff (much of it classified) to extract all sorts of data from cell phone systems. The terrorists already know a lot about these capabilities. They are not stupid, and the word gets around. But the cell phones are just too useful to abandon. The more disciplined terrorist groups are more careful, and will simply not use cell phones during some operations. But many of the anti-government forces continue to rely on the convenience of the cell phones.
American capabilities go beyond eavesdropping conversations, monitoring patterns of use ("traffic analysis") and tracking the locations of users. Where possible, U.S. troops (or, usually, their interpreters, who speak the local accent), will take over a number, or the phone itself (if the previous user is now a captive, or a corpse) and "play" the bad guys on the other end.
It's a new kind of war, much unlike previous games played on military radio networks. Everyone has a cell phone, and everyone can play, or get played.