The man behind the FB data leak said, data available to anyone who want it.

The person who leaked the data of users of Facebook to the British Firm Cambridge Analytica, Aleksandr Kogan, said that the users’ and their friend's data was available to anyone and everyone who was a developer and who needed it. He added, asserting that opt-in feature was not a special permission you had to get. “This was the core feature of a Facebook platform for years”.