The face of Facebook is answering tough questions from US lawmakers. CEO Mark Zuckerberg is testifying about a security breach that affected as many as 87 million users of the popular social media platform. The social media giant admits it did not do enough to stop a data-mining company from using that information to try to influence the 2016 US presidential election. CGTN's Jim Spellman reports.

Facebook CEO Mark Zuckerberg -- taking questions from US senators as he seeks to reassure lawmakers, the financial markets and users about online privacy concerns.

MARK ZUCKERBERG CHAIRMAN AND CEO, FACEBOOK "We didn't take a broad enough view of our responsibility and that was a big mistake, and I am sorry. I started Facebook, I run it, and I'm responsible for what happens here."

The social media platform has faced criticism after it was revealed that data from as many as 87 million Facebook users was transferred without their consent to Cambridge Analytica - a political consulting firm used by the Trump presidential campaign. Facebook has also been criticized for allegedly allowing Russian operatives to use the social media platform to try to influence the election and for allowing the spread of fake news and hate speech. Zuckerberg says he underestimated how powerful his company would become.

MARK ZUCKERBERG CHAIRMAN AND CEO, FACEBOOK "We've made lots of mistakes running the company- I primarily viewed Facebook as building tools to connect people- I now recognize we need to take a more proactive role and broader view of our responsibility. Committed to getting this right. People will see a real difference."

Zuckerberg says Facebook will take measures meant to better protect user data including: Limiting what data developers can access to only the name, profile photo and email address of users. Remove developer access to that data if the user hasn't accessed an app for three months and increased transparency for political advertisements. Some lawmakers say those changes may not be enough, and new laws may be put into place to regulate Facebook and other social media platforms.

BILL NELSON US SENATOR "If you and other social media companies do not get your act in order, none of us are gonna have any privacy anymore."

JIM SPELLMAN WASHINGTON "Facebook hopes to avoid the kind sweeping regulation that could limit the company's ability to make money using the data it collects, but there are indications it is open to some regulations that would increase rules applied to political and issue ads appearing online. Jim Spellman, CGTN, at the US Capitol, Washington."