Stop mobile phone theft

There is a way to disable ytour set so taht if its stolen, the thief cannot use the cell phone. There's a unique number behind your cellphone where your battery is kept. You need to give that number via phone to your phone company(i think) and they'll disable the phone (not just the SIM card). There's also a new system that tracks down stolen cell phones. One of my friends had their cell phone stolen, and she reported her serial number and got it disabled.