IPhone
Jailbreaking

Apple restricts the installation of unapproved third-party apps and does not allow full access to the iPhone's filesystem. According to Jonathan Zittrain, the emergence of closed devices like the iPhone has made computing more proprietary than it was in the PC era. Jailbreaking allows users to install apps not available on the App Store, customize their device in ways not allowed by Apple, and bypass SIM locks without carrier approval. Some jailbreak tweaks were later copied by Apple and implemented into iOS, like multitasking, widgets, and copy and paste.

Apple attempted to use the DMCA to fight jailbreaking; however in 2010, the U.S. found jailbreaking to be legal. Jailbroken iPhones are at higher risk of malware due to Apple’s lesser control of the app ecosystem. In the United States, Apple cannot void an iPhone's warranty solely due to jailbreaking. Jailbreaks rely on exploits. Apple has improved the iPhone's hardware and software security, making these exploits harder to find; as a result, recent iPhones cannot currently be jailbroken.
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