At one time or another, many people with Apple iOS-based devices, such as the iPhone, iPad or iPod touch, have looked into "jailbreaking" them.
Jailbreaking means bypassing the restrictions Apple puts on the operating system and taking full control of the device. With a jailbroken device, you can install apps and tweaks that aren't authorized by Apple, but you also remove the tough security protections that Apple has built into iOS.
The process of jailbreaking your iPhone, iPad or iPod touch is legal in the U.S. for the time being. What is certain is that Apple considers jailbreaking a violation of its warranty, so if something goes wrong during the process, it's up to you to fix it.
(Jailbreaking is not the same as unlocking, which permits you to change carriers while keeping the same handset. For more, read: Jailbreak, Root or Unlock: What's the Difference?)
Here are five benefits of jailbreaking, followed by five serious risks.
If your device is jailbroken, you can install apps that aren't available from the iTunes App Store. For example, Cydia is a framework that lets you add other unauthorized apps, such as games and networking tools.
"Apple is fairly restrictive. A lot of applications don't make it into their marketplace," said Tim Armstrong, a security specialist at Boston-based Threat Stack.
Ever wanted to use your iPhone or cellular-enabled iPad as a broadband modem, or as a Wi-Fi hotspot, to connect your laptop to the Internet?
Cellular carriers offer this service, called "tethering," but often charge for it or include it only as part of high-priced plans. Owners of jailbroken devices can do it for free, thanks to unauthorized apps such as MyWi, available through Cydia.
"Phone providers don't want you to use apps like the tether app, but people do it anyway," Armstrong said.
If you want to alter your iPhone's or iPad's look and feel, there are plenty of themes available on Cydia to change your icons, wallpaper, dock and status, according to Armstrong.
There's also a powerful customization app called WinterBoard that lets you do all of the above, plus customize sounds, all in one go. However, it won't work on an iPad, according to Brent Morris, a security analyst at GoPro in Carlsbad, California.
Jailbreaking exposes the inner workings of an iPhone, iPad or iPod Touch to its user, which can be very useful.
For example, installing a secure shell (SSH) client lets you securely move data between two devices on a network. Using SSH, you can connect your jailbroken iPhone to your computer and fix corrupted files, or install games that aren't available in the iTunes App Store.
"SSH is almost like a tweak to jailbreak," Morris said. "However, since SSH gives anyone the ability to remotely connect, the first thing you must do is change the [administrative] password. The default password is 'alpine' and everybody knows it. So if you don't change it, everyone can get into your phone."
You can "unlock" your jailbroken iPhone or iPad to go from one cellular provider to another at will, as long as they're both carriers that use the GSM wireless standard, and, sometimes, the LTE standard as well. All you need to do is change the Subscriber Identity Module (SIM) card. All iPhone 5 and later handsets are compatible with both GSM and LTE.
Most U.S. carriers used to lock their handsets for the life of the unit, but as of February 2015, the carriers have been required by law to unlock a phone as long as the phone is fully paid for (i.e., the contract, lease agreement or hardware payment plan has completed) and the account is "in good standing" (i.e., you have made all the payments so far).
Yet policies among the major carriers still vary greatly. Verizon now locks almost none of its handsets, and none of its iPhones, but AT&T, Sprint and T-Mobile still do. Most of them require that your payment obligations have been fulfilled before they will unlock a handset, but will usually unlock a device for international travel or if the customer is a U.S. military service member being deployed overseas.
Unlocking won't work for older Sprint or Verizon iPhones or iPads, such as the iPhone 4 and earlier, that use the CDMA wireless standard and aren't LTE-compatible. For those, you'd have to bring your device into the desired carrier's retail store, where a technician might be able "flash" its firmware to the new network.
Things get complicated with the iPhone 4s and the iPhone 5, iPhone 5c and iPhone 5s. Every iPhone 4s can use either GSM or CDMA, but the CDMA radio is switched off on handsets meant for GSM networks, and vice versa. Ask the carrier if it can activate the other radio.
Meanwhile, every iPhone 5, 5s and 5c can use GSM, but only some can use CDMA as well. Beginning with the iPhone 6, Apple has made every handset compatible with both CDMA and GSM, although LTE bands may still vary among regional models.
Jailbreaking absolutely makes your iPhone, iPad or iPod touch an easier target for malware. It completely removes the walls that Apple built into both iOS and the iTunes App Store. Most documented malware for iOS has affected only jailbroken devices.
"You can install an app from any website you want, and you'll never know if you're downloading a program that contains malware," Armstrong said.
You really don't know how secure your device will be after it's been jailbroken. That's because you've fundamentally changed the whole operating system, according to Armstrong.
"A lot of people don't realize what they're doing," he said. "When you launch the jailbreak, you're defeating the security of the phone. Once you do that, every application has full access to the phone and you put trust in the people who create the apps."