https://www.cnet.com/news/facebook-apple-samsung-cambridge-analytica-user-data-and-their-friends-data/

According to an extensive report by the New York Times, Facebook reached agreements with at least 60 different device makers -- including companies like Apple, Microsoft, Samsung and Blackberry -- providing access to large amounts of user data. More significantly, the agreements provided access to friend's data, raising compliance issues with a 2011 consent decree with the Federal Trade Commission.

The report states that the data of users' friends was often made available without explicit consent.