Effect of erasing an iPhone on the Find My iPhone feature

Q: So even if my stolen iPhone 5 is wiped clean and restored through iTunes by a thief, and the thief decides to put the iCloud feature “Find My iPhone” back onto my stolen iPhone 5, and he also turns the “Location Services” back on in order that nobody will be able to steal the phone from him without him being able to track it, are you telling me that I still can’t track my iPhone even though it’s my phone, and “Location Services” and “Find My iPhone” features have been turned back on? Please tell me this isn’t the case, it just doesn’t seem right? Please get back to me and let me know.

– Reader comment on Reliability of the Find My iPhone Feature

A: Actually, this is entirely correct, and is simply an inevitable function of the way that iOS and the Find My iPhone feature works.

All of the information stored on your iPhone is stored entirely in the iPhone’s flash memory. This includes the iOS operating system, your apps and media content, your configuration settings, and any other personal data. While the operating system is stored in a separate area, for various reasons this is read-only during normal operation—it can only be written to when you’re actually performing a software update or a full iOS restore from iTunes.

As a result, all of your settings and configuration information is stored in the same memory space as your media content, apps, and other personal data. When the iPhone is wiped—either by a Remote Wipe command or by somebody manually erasing it—this configuration information goes away entirely. After a wipe operation, the iPhone is returned to the same configuration that it was in when it was brand new; to put it another way, at that point it’s no longer “your” iPhone as far as iOS is concerned.

Remember that the Find My iPhone feature is connected to your iCloud account. If the thief enabled the Find My iPhone feature, they would be doing it under their iCloud account, not yours, so it could only be tracked using that account.

In fact, the only identifying information that would remain on an iPhone after it is wiped would be whatever is stored on your SIM card, which is just information such as your phone number that identifies your device to the cellular network. Not only can this not be used to track your phone, but it is trivial for a thief to remove the SIM card, and if your iPhone has been stolen it’s normally wise to have your carrier deactivate it to prevent a thief from accumulating charges on your behalf.

While it would theoretically be possible for Apple to create a Find My iPhone feature that would continue to work after a full wipe of the device, this would require some significant re-engineering of iOS and perhaps even the iPhone hardware itself. Further, since this would require personal details and configuration settings to be stored separately and in a more permanent manner, this would also present some additional privacy concerns with regard to the used iPhone market.

It’s also worth keeping in mind that this isn’t any different from any other mobile platform or computer operating system. For example, the Blackberry Protect service works in much the same manner, and Android devices don’t offer a built-in equivalent feature at all, requiring the use of third-party apps or services; neither will survive a complete wipe of the device, which in all cases makes it a “new” device.