The best way I have found is to set a password in Settings > General > Restrictions. Over here, you must disable that any changes can be made to Contacts.
Obviously a passcode or a password will prevent someone from getting in to turn it off.
Location services, yes. The device? No. You can turn off an iPhone that uses passcode or password without it. Takes about 10 seconds. Has the same effect as turning location services off.
Sent TC an email about this but never got a response.
Anyone can go into Settings > Location Services, then Turn off location services.
This message will pop up
Turning off Location Services will no longer enable you to locate your ipad on a map with "Find My iPad"