The Copyright Office has granted DMCA exemptions for jailbreaking making the procedure legal in the United States in the next years.
Jailbreaking an iOS mobile device it is possible to remove hardware restrictions implemented by the Apple's operating system, Jailbreaking gives users root access to the iOS file system and manager, this allows them to download and install applications and themes from third-party stores.
Is the jailbreaking legal?
Differently from the past, now it is legal in the United States because the Copyright Office has granted DMCA exemptions for jailbreaking.
"jailbreaking refers to the process of gaining access to the operating system of a computing device, such as a smartphone or tablet, to install and execute software that could not otherwise be installed or run on that device, or to remove pre-installed software that could not otherwise be uninstalled" is the definition for jailbraking provided in the Register document.
Under the new law jailbreaking mobile computing devices and smart TV is now legal.
Saurik, the popular Cydia's developer is one of the architects of change
More details are available in the Register of Copyrights document (page 172).