Facebook CEO Mark Zuckerberg faced off with lawmakers in a marathon 5-hour hearing Tuesday about how the voter-profiling company Cambridge Analytica harvested the data of more than 87 million Facebook users, without their permission, in efforts to sway voters to support President Donald Trump. This is Zuckerberg being questioned by California Senator Kamala Harris.

Sen. Kamala Harris: “I’m also concerned that—when you personally became aware of this, did you or senior leadership do an inquiry to find out who at Facebook had this information, and did they not have a discussion about whether or not the users should be informed, back in December of 2015?”

Mark Zuckerberg: “Senator, in retrospect, I think we clearly view it as a mistake that we didn’t inform people. And we did that based on false information, that we thought that the case was closed and that the data had been deleted.”

Sen. Kamala Harris: “So there was a decision made, on that basis, not to inform the users. Is that correct?”

Mark Zuckerberg: “That’s my understanding, yes.”

We’ll have more on the 5-hour hearing and Facebook’s privacy scandals after headlines.