https://www.cnbc.com/2018/06/08/facebook-gave-some-companies-access-to-data-of-users-and-their-friends-past-2015.html

Facebook formed special deals with select companies that granted them access to the data of users and their friends well past 2015, when the social media company said it cut off developer access to that information, according to a Wall Street Journal report.

Referred to as "whitelists," the special agreements allowed companies to access information, like phone numbers of users' friends and degree of closeness between users, according to the Wall Street Journal.