Twitter sold public data access to Aleksandr Kogan, the Cambridge University academic who also obtained millions of Facebook users’ information that was later passed to a political consulting firm without the users’ consent. Twitter confirmed the development first to UK newspaper the Telegraph (link behind paywall).

Kogan, who created a personality quiz on Facebook to harvest information which he later sold to Cambridge Analytica, established his own commercial enterprise, Global Science Research (GSR). That firm was granted access to large-scale public Twitter data, covering months of posts, for one day in 2015, according to Twitter.

“In 2015, GSR did have one-time API access to a random sample of public tweets from a five-month period from December 2014 to April 2015,” Twitter told Bloomberg. “Based on the recent reports, we conducted our own internal review and did not find any access to private data about people who use Twitter.” The company has removed Cambridge Analytica and affiliated entities as advertisers. Twitter said GSR paid for the access; it provided no further details.

Cambridge Analytica has also commented on the issue, telling Reuters that, never received Twitter data from GSR or Aleksandr Kogan, and has never done any work with GSR on Twitter data.

Who is Aleksandr Kogan?

In 2015, Aleksandr Kogan, a psychology professor at Cambridge University, created an app named “thisisyourdigitallife” that promised to predict aspects of users’ personalities. Around 270,000 people downloaded the app and signed in using their Facebook accounts, giving Kogan access to information about their city of residence, Facebook content they had liked, and information about their friends.

Through Kogan’s company Global Science Research, hundreds of thousands of users were paid to take a personality test and agreed to have their data collected for academic use. Kogan passed the data to Cambridge Analytica’s parent company Strategic Communication Laboratories (SCL), in violation of Facebook rules that prevent app developers from giving away or selling users’ personal information.

How did Kogan and his buddies access data from 87 million profiles despite only 270,000 people using their app? Back in 2015, Facebook also allowed developers to collect some information from the friend networks of people who used Facebook Login. That means while a single user may have agreed to hand over their data, developers could also access some data about their friends. Facebook says this was part of their terms of service but it has subsequently been changed to limit something like this. Through those 270,000 people who opted in, Kogan was able to get access to data from some 87 million Facebook users. That data could have included information about people’s locations and interests, photos, status updates and check-ins.

How Twitter sells access to data

A report on Bloomberg explains that Twitter provides certain companies, developers and users with access to public data through its application programming interfaces (APIs). For context, APIs or Application Programming Interfaces are a software layer that allows applications to access features or data from a platform like Twitter. The company sells the data to organizations or companies, which often use them to analyze events, sentiment or customer service.

Enterprise customers are given the broadest data access, which includes the last 30 days of tweets or access to tweets from as far back as 2006. To get that access, the customers must explain how they plan to use the data, and who the end users will be. Twitter doesn’t sell private direct messaging data, and users must opt-in to have their tweets include a location. While unveiling its earnings for Q1 2018  last week, Twitter reported that “data licensing and other revenue” grew about 20%, to $90 million.