The so-called Open Graph API included not only a user's name, birthdate, politics, and religion—private direct messages could be requested too—but also his or her friends' data.

Facebook's old API, the tool that gives third parties access to user data, provides insight into what would have been possible to obtain before 2014.

The Facebook personality quiz at the centre of the Cambridge Analytica scandal was not an isolated incident. For five years, the Graph API left a gaping hole in Facebook’s defences.

Yandex hits too close to Graph Search with Wonder, and Facebook comes back at it by pulling integration.