Q: How well does the “Find My iPhone” (or iPad) feature actually work? I mean, I know that I can use it to locate my iPhone and wipe it or lock it, but can I really rely on it to help get my iPhone back if a thief steals it? Can’t somebody just turn my iPhone off after they steal it, or am I missing something here?

– Brenda

A: No, you’re not really missing anything here at all as you’re exactly right that the Find My iPhone feature won’t work if your iPhone is completely turned OFF. In fact, there are a number of situations in which the Find My iPhone feature will not be available:

If your device has no passcode, a thief can go into your iCloud settings and turn off the Find My iPhone feature just as easily as you can.

If your device has no data coverage, then obviously it cannot communicate with Apple’s iCloud servers to either report its location or receive instructions that you may send to it. In the case of a Wi-Fi only iPad or an iPod touch, this is very likely to be a problem unless the device is near an already-configured Wi-Fi network such as at your office, school, or a coffee shop that you frequent, or if the person who has your device can get into it and has configured it for another Wi-Fi network. Even with an iPhone, however, removing the SIM card, or travelling out of cellular data coverage will break access to the Find My iPhone feature.

Note that this creates an additional dilemma for iPhone users, since if you call your cellular carrier and cancel/suspend your plan, you’ve effectively risked cutting your device off from the Find My iPhone feature; however if you don’t cancel your plan, you risk having a thief rack up expensive long distance calls on your account. A standard iOS passcode lock will prevent somebody from accessing your device in order to place non-emergency calls, but a thief can just as easily wipe and restore your device and then proceed to use the device—and your cellular account—however they see fit.

In the very least, you may want to engage Lost Mode or remotely wipe your device before cancelling service just to make sure that it’s at least secured with a passcode or erased entirely in order to protect your data.

If your device is erased and/or restored to factory settings, then the Find My iPhone feature goes away with it. Find My iPhone is a software feature built into iOS—it’s not embedded in the hardware in any special way. In essence, if somebody restores your iPhone to factory settings and configured it themselves, it’s not really your iPhone any more as far as iCloud is concerned.

If your device has a passcode, it will be more difficult for a thief to wipe it before they are able to get back to a computer, but they can still simply switch it off to block the Find My iPhone feature in the meantime.

Remember that all of the security features built into iOS are there to protect your data, not your device. It doesn’t matter how strong your passcode is nor how reliable Find My Friends is, if an experienced and determined thief has deliberately stolen your device, they will have a hard time accessing your information if it’s properly secured, but they will basically have scored themselves a shiny new iPhone to do with as they please.

At the end of the day, if you’re afraid your iPhone has fallen into the wrong hands, you’re basically going to be need to decide whether to send a “remote wipe” to protect your information, cancel your cellular account to protect your wallet, or leave everything active and hope that the Find My iPhone feature allows you and/or the police to track it down before the thief can disable it.