Also, if a jailbroken device is lost or stolen, you can pretty comprehensively understand what data may have been exposed, because you will be able to pore through all the other data stores on the device, such as the SMS/iMessage texts, address book, calendar, some (but not all) keychain items, and other system files that you'd normally be prohibited from exploring forensically. (You would do this by restoring from backup the data from the missing device onto a replacement device, which you would then jailbreak.) That can help you determine the risk exposure after a device has gone missing. Be warned that this process is time-consuming and costly, but in some cases it will be worth the effort.
The bottom line is that jailbreaking can be exhilarating and liberating, but it shouldn't be done by anyone who isn't willing to swim in an open sea of noncurated apps. For the vast majority of users, this translates to unnecessary and unjustifiable risks. Just walk on by.
With more than 20 years in the information security field, Kenneth van Wyk has worked at Carnegie Mellon University's CERT/CC, the U.S. Deptartment of Defense, Para-Protect and others. He has published two books on information security and is working on a third. He is the president and principal consultant at KRvW Associates LLC in Alexandria, Va.
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