What is Jailbreaking an iPhone?

Like any device from a company, Apple made the iPhone so that the only way to get new apps onto them was to get them directly from the Apple App store. Hackers across the world thought that this was no fun, since it limits the apps to things that Apple will approve. From this fact, the practice of jailbreaking iPhones has become a hot topic.

What is Jailbreaking?

To Jailbreak an iPhone is to go through a process that allows that phone to run third-party unsigned code by opening up the operating system. This freedom of the system allows iPhones to be more like any other computer--completely in the power of the user who can download whatever they want. Once it is jailbroken, an iPhone can download many new themes and extensions which weren't available through the app store through a program called Cydia.

How do people do it?

People jailbreak their iPhones using one of a few different programs available on the internet. These are all freeware, so there is no cost to download them and jailbreak your iPhone. Cydia installer founder Jay Freeman estimates that over 10% of all iPhones are jailbroken. The only consequences of jailbreaking are that it can make your iPhone more susceptible to viruses which couldn't touch an un-jailbroken device. This was demonstrated in early November 2009 when the first iPhone worm was created by 21-year-old Australian technical college student Ashley Towns of Wollongong. He told Australian media that he created the worm to raise awareness of security issues. The worm was essentially a harmless demonstration, but it paved the way for a potential of future iPhone viruses.

Is Jailbreaking Illegal?

Surprisingly, jailbreaking an iPhone is actually 100% legal and has been deemed so by Apple itself and courts. There is no law that says a device must remain locked if that is the way the provider designed it. Because this is good, clean hacking fun that is legal in every way, jailbreaking is a popular way to make your iPhone able to do more than ever before. The iPhone Dev Team are a group of hackers who have developed most of the free software for jailbreaking to date. It is estimated that 1.6 million devices worldwide use a Dev Team program. The iPhone 4 has yet to be jailbroken, but it no doubt soon will be.

Source: http://en.wikipedia.org/wiki/IOS_jailbreaking