The freshman congresswoman stumped the Facebook exec with a question about whether, hypothetically, if she wanted to run an ad on Facebook claiming (incorrectly) that Republican lawmakers supported the Green New Deal, Facebook would allow that:

Rep. Alexandria Ocasio-Cortez (D-N.Y.) had Facebook CEO Mark Zuckerberg stumbling for words during a congressional hearing Wednesday afternoon, and people on Twitter were totally living for it.

Here is @AOC 's full questioning of Mark Zuckerberg. "Could I run ads targeting Republicans in primaries saying that they voted for the Green New Deal?" pic.twitter.com/VrGQw7UzIW

The Silicon Valley billionaire was unable to answer the question, responding with, “Congresswoman, I don’t know that off the top of my head.”

“So you don’t know if I’d be able to do that,” Ocasio-Cortez shot back.

“I think probably,” said Zuckerberg.

The Facebook creator appeared before the House Financial Services Committee for questioning over Facebook’s proposed digital currency, Libra, but the hearing ended up being about a litany of the social media giant’s issues, including privacy, data, advertising and the spread of misinformation.

When asked by Ocasio-Cortez if he could see a problem with the complete lack of fact-checking for political advertising on the platform, Zuckerberg dodged the question.

“I think lying is bad, and I think if you were to run an ad that had a lie in it, that would be bad,” he said, adding later that he believed people “should be able to see for themselves” what politicians are saying so that they can “judge their character for themselves.”

Twitter users applauded Ocasio-Cortez for her fiery line of questioning: