After it was discovered that Cambridge Analytica illegally accessed the personal information of millions of Facebook users, a question remained in the mind of the public: What other data accessed Dr. Aleksandr Kogan?

Twitter confirmed for The Telegraph on Saturday that GSR, Kogan's trading company, had purchased API access to a random number of public tweets over a five-month period between December 2014 and April 2015.
Twitter told Bloomberg that after an internal review, the company did not find any access to private data for people who use Twitter.
Twitter sells API access to organizations or large companies for the purpose of observing opinions or opinions during various events, or about certain topics or ideas.
Here's what Twitter's spokesman said:
Twitter has also issued a policy decision on off-board advertising from all accounts owned and operated by Cambridge Analytica.
This decision is based on our determination that Cambridge Analytica operates using a business model that basically contradicts the acceptable business practices of the Advertisers. Cambridge Analytica may remain an organic user on our platform, in accordance with Twitter's rules.
Of course, this does not have the same scope as the data collected around Facebook users. Twitter data for users are far less personal. Location on the platform is opt-in and general in it, and users are not required to use their real name on the platform. Cambridge Analytica wrote this morning that data received by Kogan / GSR from Twitter was not purchased or used by Cambridge Analytica.