https://www.theverge.com/2018/4/10/17222444/mark-zuckerberg-senate-hearing-highlights-cambridge-analytica

Mark Zuckerberg made his highly anticipated debut before Congress today during a marathon five-hour hearing before a joint session of the Commerce and Judiciary committees. Zuckerberg remained calm and level-headed throughout, and senators were mostly polite and deferential as they sought to understand how Facebook had inadvertently allowed the profiles of up to 87 million people to be collected by the political data-mining firm Cambridge Analytica.

In the weeks leading up to the hearing, Facebook made a series of announcements designed to demonstrate that it took the data leak seriously and was working to prevent it from happening again. Zuckerberg referred repeatedly today to these changes, which include making privacy shortcuts easier to find, restricting the data shared with developers when you log in using your Facebook account, labeling political ads and making them available for public inspection, and launching a bounty program to reward people who find examples of data misuse.