During her testimony, Haugen said she is concerned with several concepts related to Facebook, such as ranking posts based on engagement, a lack of safety support for languages beyond English, and the "false choices" that Facebook presents by reducing discussions on how to act in a battle between transparency versus privacy.
"Now is the most critical time to act," said Haugen, comparing Facebook's situation to an oil spill. "Right now the failures of Facebook are making it harder for us to regulate Facebook."
Haugen also discussed the influence of "Groups" in the spread of misinformation and polarizing content.
"Unquestionably, it's making hate worse," she said.
Haugen suggested solutions that would help curb the spread of misinformation and shift away from ranking based on engagement, such as a return to updates to users' news feeds that happen chronologically.
However, Facebook has pushed back from changes that could impact its bottom line, she said.
"They don't want to lose that growth," said Haugen. "They don't want 1% shorter sessions because that's 1% less revenue."
Haugen also addressed Facebook's Oversight Board, the body that makes decisions on content moderation for the platform. Haugen implored the board to seek more transparency in its relationship with Facebook.
Haugen said if Facebook can actively mislead its board, "I don't know what the purpose of the Oversight Board is."