Many third-party apps are very keen to have full access to your demographic Facebook information.
Here’s what happens when I gave a quiz app access to only my pictures, and nothing else (age, gender, nationality, etc.).
Yesterday it paired me up with two married men (I’m straight) and told me I’m eighty-nine, and a bank robber among other things.
Not a bad way to waste a half hour. But I’m not terribly trusting of digital prophets.