There are many applications and tools present in the market that can trace your mobile device in case it is stole or lost. Some methods involve using the IMEI numbers to track stolen mobile devices while other methods send an SMS to a predefined mobile number whenever SIM card in a specified mobile device is changed.
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Now Apple has come up with another method for detecting theft of mobile device for which it received a patent on July 26, 2011. The patent is US7986233, entitled "Acceleration-based theft detection system for portable electronic devices". The patent describes a theft prevention system which uses an accelerometer to detect theft. The accelerometer determines the frequencies characteristics of the movement of the mobile device to determined whether the mobile device is stolen or not.
The claims reads:
"A theft detection system, comprising: a graphical user interface configured to display a theft detection system menu and arranged to provide assistance to a user, wherein the assistance includes initiating the theft detection system and configuring the theft detection system to initiate an output of an alarm using an output device when a theft condition is present wherein when the theft detection system is not active, the graphical user interface receives a user input event at the theft detection system menu for activating the theft detection system, otherwise, the graphical user interface receives a user input event at the theft detection menu for configuring the theft detection system; a memory device; an accelerometer arranged to generate an acceleration signal in accordance with an acceleration of the device, wherein the acceleration signal includes frequencies characteristic of movement of the device; and a processor arranged to determine if the theft condition is present, wherein the processor determines if the theft condition is present by processing the acceleration signal by isolating the frequencies characteristic of movement of the device detecting acceleration signal frequencies below a threshold frequency indicative of the theft condition, detecting acceleration frequency spectra of the detected acceleration signal frequencies that are characteristic of the theft condition, scanning for at least one frequency profile consistent with at least one theft condition, comparing the detected acceleration frequency spectra to the at least one frequency profile, sending a theft detection signal only when at least one acceleration signal frequency below the threshold frequency is detected and based on the comparing, the detected acceleration frequency spectra are determined to be characteristic of the theft condition, and initiating the production of an alarm based upon the detected theft condition."
Source: Freepatentsonline.com and USPTO