The API (application programming interface) allowing to detect abnormal usage of mobile terminals equipped with Apple operating system, IOS has been deactivated by the company in version 4.2.1 of this operating system. This API allowed, among other possibilities, whether the device had been unlocked (jailbreak) to use applications not certified by Apple.

This move comes after this summer, U.S. officials stated that the release was not illegal. The Copyright Office of the United States legalized the breaking of the protection of mobile and other devices to allow the execution of applications software . Apple had opposed the measure. Apple had conducted a campaign against it, claiming that its iPhone unlock the door open "the possibility of damage and defects to mobile phone operation and its applications.

According to the manufacturer, received millions of cases of trouble for the release of their iPhone. Legitimizing the release of virus would mean an increase in equipment. Apple never sued any iPhone owner to break their security system, but in February 2009 estimated that more than 400,000 had. The decision has now taken is based less, analysts said, in a change of the company but to prevent the emergence of systems capable of lying to conceal the API and the terminal has been really unlocked while the above API sends a signal to the contrary. It would, therefore, a decision linked to security.