jailbreak

to unlock the operating system of a mobile phone or other device so that it can run software which it is not normally authorized to use because of restrictions imposed by the device's manufacturer

In July 2010, regulators in the US announced that there was no law which prohibited the action of manipulating the operating system of an iPhone in order to circumvent the restrictions it imposes on software use. To adopt popular terminology, they were in other words declaring that the action of jailbreaking a smartphone was not illegal, and thereby unwittingly galvanizing the conversion of noun to verb.

the concept of jailbreaking is most often associated with products … such as the iPhone, iPod and iPad, which routinely restrict the user to applications licensed exclusively by Apple

If someone jailbreaks a smartphone, tablet (computer) or other device, they use a special piece of software in order to remove the restrictions imposed by the manufacturer on the kind of applications that can be downloaded and run on the device. The concept of jailbreaking is most often associated with products from Apple Inc., such as the iPhone, iPod and iPad, which routinely restrict the user to applications licensed exclusively by Apple and purchased via its App Store. As well as wanting to lift the restriction on what kinds of applications they can purchase, those who jailbreak often do so as a reaction against what they perceive as a form of censorship imposed by Apple Inc. in only allowing the use of their 'approved' apps.

As the market has developed and competing products have become more widely available, the word jailbreak has in turn gained currency, since users often encounter similar restrictions imposed by manufacturers other than Apple Inc. The meaning of jailbreak has therefore broadened to describe any act of bypassing what is often referred to as digital rights management (sometimes abbreviated to DRM) – any form of technology which inhibits the use of digital content simply because the manufacturer does not want or approve it.

Background – jailbreak

The concept of jailbreaking dates back to July 2007, when it was applied to the iPhone within a month of the device's first release. This first occurrence related to the adding of custom ringtones, but the idea quickly developed as a means to augment the phone with games and other applications not licensed by Apple Inc. Notable in the history of jailbreaking are a group of engineers popularly known as the iPhone Dev Team, who have developed a number of tools to enable use of unauthorized applications on a range of devices by Apple and other manufacturers.

The word jailbreak, in the sense of overriding restrictions on a smartphone etc, can be used as both a countable noun and a verb. As a noun, it can refer either to the act itself, or to a software tool used to perform the action. As a verb it works transitively, with past tense and past participle forms jailbroke and jailbroken (and alternatively, though less commonly, jailbreaked). Jailbroken is sometimes used as a participial adjective to describe a device which has been manipulated in this way. There's also some evidence for a derived noun jailbreaker to refer to a person involved in the activity.

Use of the word jailbreak to refer to this concept is based on the idea of 'setting something free', a kind of metaphorical spin on its original use as a noun meaning 'an escape from prison'.