It can be very easy to turn off Find My iPhone if you don't have a passcode on your iPhone, iPad, or iPod touch. If you want to keep someone from turning it off the perform the following steps: launch the Settings App, tap General > Restrictions > Turn on Restrictions. You'll be prompted for a four digit passcode and then again to verify it. This passcode can be, and should be, different than the one you use to lock the screen. Finally, under the section titled Allow Changes turn the switches off for Location and Accounts.
No one will be able to turn off location services or Find My iPhone without the passcode. This is great if your iPhone is stolen, but not so when you are using your phone or apps that require location services. In the event that an app requiring location services isn't working you'll need to go back to the Allow Changes section and turn it on. Relaunch the app, after forcing it to quit, and try again. Once you get it working toggle the Location switch back to the off position.
Compatibility: iPhone, iPad, and iPod touch.
