No. Cambridge Analytica scraped data via the Graph API, which was open for apps to use.

The original idea with the API was that apps could become more social - for example, Spotify had a Facebook integration that’d show which of your friends use Spotify, and their favourite playlists (if they chose to share them). To handle this, the API granted access to not only your data, but some of your friends data. Keep in mind, this was all public profile data that people chose to make visible to public or at least to their friends.

That was fine when people were legitimately using it, but there were bad apps that didn’t follow the rules. Cambridge Analytica scraped data via a quiz app. People would click a link and log in to a quiz app on Facebook. The log in page shows a list of the data types that’d be shared, but people still logged into it. They’d then scrape all accessible data for both the person that logged in, as well as the data their friends had shared.

The API is very locked down now. People that use the API have to have a privacy audit of some sort, and much less data is available. A lot of people don’t like the API being so locked down (for example, it’s impossible to make third-party Facebook apps), but there really wasn’t any other choice.