Facebook CEO Mark Zuckerberg among victims of personal data theft

Facebook CEO Mark Zuckerberg says his Facebook data was included in the personal information sold to malicious third parties, a reference to the Cambridge Analytica scandal that has rocked his company over the past several weeks. 

Facing his second day of questioning from members of Congress on Wednesday, Zuckerberg was answering a question from Republican Anna Eshoo, a Democrat from California.

Facebook has said that 87 million people's personal data was scooped up when some 270,000 users took a personality quiz and had not just their data, but the data of their friends to be accessed by an outside app.

Cambridge Analytica then obtained this data and is said to have used it to try to influence elections around the world. 

Zuckerberg says he believes it is "inevitable" that there will be regulation of his industry. 

Lawmakers in both parties have floated possible regulation of Facebook and other social media companies amid privacy scandals and Russian intervention on the platform. It's not clear what that regulation would look like.

Zuckerberg said at a House hearing today that it is "inevitable that there will be some sort of regulation." But he warned that lawmakers should be careful in what they propose. He noted that larger companies like Facebook have more resources to comply with regulations than small startups.