You might think your expensive iPhone is safe because you've setup Apple's Find My iPhone app.

But muggers and pick-pockets aren’t tech idiots, however, and have various ways of thwarting your and the police’s attempts to locate your stolen iPhone.

One of the easiest ways a thief can block Find My iPhone’s abilities to locate your iPhone is to simply switch off the phone’s location services.

Stopping this is easy.

1. Open Settings on your home screen
2. Open General
3. Select Restrictions
4. Set a Restrictions passcode by clicking Enable Restrictions. Use a different code than your Unlock passcode, just in case the mugger forces you to reveal that.
5. Scroll down the list of Restrictions until you find the “Allow Changes” list
6. Open Location
7. Select the “Don’t Allow Changes” option so that it’s ticked

Now that you’ve done this the thief or next person to get hold of your iPhone shouldn’t find it easy to disable your location service that will help you or the cops track it down.

You can also use Restrictions to stop others deleting applications from your iPhone, such as Find My iPhone  which needs to be installed on the device for all this to work. This does make deleting apps a bit more long-winded than usual but unless you’re in the habit of often deleting apps it’s a wise precaution.

Find My iPhone setup

Important: Make sure that you’ve set up Find My iPhone correctly in the first place.

1. Open Settings on your home screen
2. Open iCloud
3. Ensure Find My iPhone is switched to On.
4. Go back to Settings
5. Ensure that Location Services is On.
6. On the same screen scroll down to Find My iPhone, and set it to On.
7. Make sure that the date on your device is correct. This can be set in Settings > General > Date & Time
8. Check that your device is up to date. It needs to have iOS 3.1 or later (iOS 4.2 recommended, required for free users).
9. Use the same Apple ID (iCloud account) on each device you set up.

Simple post-iPhone theft insurance advice

If your iPhone is properly insured (check now with your home contents insurance! NOW) you may prefer to simply contact your network provider immediately to disconnect it as soon as possible. And make sure you report the theft to the police. If you want to inconvenience the thieves then first go through Find My iPhone to set a lockcode (if there wasn’t one on there to start with) and wipe it.

Also important: Write down your phone's serial number for police reports and in case it is located later on.

Other iPhone theft/security points

If you contacted your service provider to report your iPhone or iPad lost or stolen before locating/wiping your phone, and they deactivated your SIM card or account, you will no longer be able to locate, display a message on, or remotely wipe your iPhone.

If the iPhone or iPad is turned off, the map will display its last known location, not its current location (unless the same). When it's turned back on, the map will update. The same is true if you instruct the Find My iPhone to install a lockcode. It should wait until the device is turned on again, and then lock the miscreant out.

Don’t wipe your iPhone or iPad too quickly, as this might further protect you from identity or other intellectual theft but will disable Find My iPhone – so it’s unlikely you’ll ever get it back. Ditto, cancelling your SIM. This does leave you open to call charges if the thief uses your phone, but still gives you a fighting chance of locating the device.

Even when turned off, if you instruct the Find my iPhone service to do anything (display message, remotely wipe, etc) it will do that the next time the iPhone is powered on as long as your iCloud login is there. If the thief or person in possession of the iPhone or iPad wipes it clean or removes your iCloud information, it will not be found.