Facecrooks security reports a recent proof-of-concept test allowed phone numbers set to the “public everyone” status to be collected.  Users should lock down privacy settings in social networking sites.

http://facecrooks.com/Internet-Safety-Privacy/Hacker-Collects-Thousands-of-Phone-Numbers-Using-Graph-Search.html

QUOTE: On March 5, Copley reported a tip to Facebook pointing out the security flaw in Graph Search. Facebook wrote him back acknowledging the problem, though they said that all they can do to remedy it is to encourage users to strengthen their security settings. He gathered the massive database of numbers as a response to them, using API tokens to perform millions of searches for phone numbers.