https://www.theregister.co.uk/2018/04/17/former_cambridge_analytica_staffer_brittany_kaiser_dcms_committee_evidence/

The number of Facebook users whose data was compromised via quizzes "is much greater than 87 million", Cambridge Analytica's former director of program development has told MPs.

In written evidence (PDF) to the Digital, Culture, Media and Sport Committee, Brittany Kaiser wrote: "Cambridge Analytica and other unconnected companies and campaigns were involved in these activities."