->@Elmer Fudd: "Turn off the Find My Phone function off.. Permanently."
You don't have to turn off the Find My iPhone function. This will do it:
-Settings
-Privacy
-Location Services
-Share My Location - Turn that fucker off!
As others have said, if you've already enabled sharing your location with SO and family, you've got bigger problems than just changing that privacy setting. Disabling sharing your location will be evident to others you've allowed sharing with, and it may even show up automatically in the text string of each person you've previously authorized sharing with.
I'm not familiar with the spoofing thing Gotta Be Damned pointed out, but as he said please let us know if it works.