Congress on Friday officially requested that Facebook CEO Mark Zuckerberg testify about the Cambridge Analytica data breach and what Facebook is doing to prevent similar breaches from happening in the future.

“In comments to the press, you stated that the person with the most knowledge at Facebook about what Congress is trying to learn is the appropriate witness for a congressional hearing,” the House Committee on Energy and Commerce said in a letter. “As the Chief Executive Officer of Facebook and the employee who has been the leader of Facebook through all the key strategic decisions since its launch, you are the right person to testify before Congress about those decisions and the Facebook business model.”

[jwplayer xofmCvqo-wKJ9CRQU]

Zuckerberg told CNN in a Wednesday interview that he would be “happy” to testify to Congress “if it’s the right thing to do.”

“What we try to do is send the person at Facebook who will have the most knowledge about what Congress is trying to learn,” he said, referencing other lower-profile instances where Facebook has been called to testify to Congress. “So if that’s me then I am happy to go.”

The recent revelation that App developer and Cambridge University scientist Aleksandr Kogan improperly shared 50 million Facebook users’ personal information with Cambridge Analytica, a data-analytics firm, has embroiled the social-media giant in controversy and threatened its stock price.

Cambridge Analytica was hired by the Trump campaign to target voters during the 2016 general election, after working for Ted Cruz’s campaign in the primaries. When the improper data sharing appeared on Facebook’s radar in 2015, the company said they made Cambridge Analytica sign a legal document promising it would delete all the data. The data firm obeyed and claims it did not use the data in the 2016 election.

“Aleksandr Kogan lied to us and violated our platform policies by passing data from an app” to Cambridge Analytica, a statement from Facebook read.

Kogan, however, has defended his actions, saying he was assured by Cambridge Analytica that passing on the data was in accordance with Facebook’s policies.

“My view is that I’m being basically used as a scapegoat by both Facebook and Cambridge Analytica,” Kogan told the BBC on Wednesday. “We thought we were doing something that was really normal and we were assured by Cambridge Analytica that everything was perfectly legal and within the limits of the terms of service.”

A Facebook staff briefing earlier this week failed to provide the answers Congress is looking for, the committee’s letter said, since employees knew little about decisions made before they worked for Facebook.