Mark Zuckerberg is back on Capitol Hill today testifying before the House Committee on Energy and Commerce following Facebook's massive data breach.

Zuckerberg was questioned by U.S. senators for five hours on Tuesday.

Zuckerberg apologized and said Facebook didn't do enough to prevent this from happening, and said he is taking responsibility as the founder and CEO.

Zuckerberg went on to say the company needs to make changes, including improving the way Facebook protects people's information and safeguards elections around the world.

He said the company is currently getting to the bottom of what happened with Cambridge Analytica and alerting all the users whose data was compromised.

Representative Pallone, is calling for more transparency when it comes to Facebook users, and what's being done with their data.