Trends: Cell phone jammers
Cell phone jammers, those devices that can block cell phones signals from working, are getting more and more popular, and as new devices come up, they are also getting smaller. The latest CX-200 is tiny, fits in a pocket, costs $70 and will block all cell phones in a 3-meter radius. There are some more expensive ones that will block a whole room.
The main reason for cell phone jamming is to remove the noisy ringing and conversations. Places like theaters and other public places often use those devices to enforce a "no cell phone" policy. However, there are still issues with these devices. First, someone could use them to disrupt other people's activities. Then, there are those cases when cell phones are critical, such as for doctors and security officers. Until there are precise laws in place to govern what is legal and what isn't, the whole jamming business will remain a questionable practice.