Privacy issues related to Find My Friends app on iPhone

"Find My Friend" app helps you to locate your contacts in world. You may also share your settings for location information and this app is found to be helpful for parents.

Credit: 9to5Mac

But is this good enough?
In a recent post on MacRumors Forums, a man found by using Find My Friends app on iPhone-4S that his wife is cheating about his going out. He posted:

I got my wife a new 4s and loaded up find my friends without her knowing. She told me she was at her friends house in the east village. I've had suspicions about her meeting this guy who live uptown. Lo and behold, Find my Friends has her right there. I just texted her asking where she was and the dumb b!otch said she was on 10th Street!! Thank you Apple, thank you App Store, thank you all. These beautiful treasure trove of screen shots going to play well when I meet her a$$ at the lawyer's office in a few weeks.

This thing brings so many privacy issues. Even if it is in between the husband and wife.
Moreover, this account or app can bring some fake things with it.