Although it has existed for over three years, Apple on Sunday updated its support page regarding unauthorized modification of iOS software. Just one day before the iOS 6.1 jailbreak, coincidental or not. The page directly refers to jailbreaking and the potential harms it can cause to your device, in addition to noting that any tampering or hacking with iOS is a violation of your end-user agreement with Apple.
— MuscleNerd (@MuscleNerd) February 5, 2013
In particular, Apple claims that jailbreaking may result in instability, security vulnerabilities, shortened battery life, unreliable voice and data, disruption of services and the inability to apply future software updates. The company also explicitly states that it has the right to refuse service to any jailbroken iPhone, iPad and iPod touch, even if that device has AppleCare or other warranty coverage.
While some might view this support page as a mere scare tactic on behalf of Apple, some of the claims it makes are legitimate ones. Poor battery life and certain stability issues can arise from jailbreaking a device, although these problems are usually minor and can be corrected. The option to restore your device to factory default settings in iTunes remains just a click away, so nobody should be panicing.