Facebook CEO Mark Zuckerberg has admitted the scraping of 50 million user’s personal data by political consultancy Cambridge Analytica was a “breach of trust between Facebook and the people who share their data with us.”

Zuckerberg’s response comes after five days of outrage following reports Russian academic Aleksandr Kogan had used a third-party app to scrape the data, which was then transferred to Cambridge Analytica for commercial and political purposes.

Zuckerberg said Facebook is changing the way it shares its data with these type of apps as a result of the breach.