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WATCH: ‘I’m sorry,’ Zuckerberg says as he opens Senate hearing with apology

WASHINGTON — Facebook CEO Mark Zuckerberg began a two-day congressional inquisition Tuesday with a public apology for a privacy scandal that has roiled the social media giant he founded more than a decade ago.

Zuckerberg opened his remarks before the Senate Commerce and Judiciary committees by taking responsibility for failing to prevent Cambridge Analytica, a data-mining firm affiliated with Donald Trump’s presidential campaign, from gathering personal information from 87 million users to try to influence elections.

Zuckerberg had apologized many times already, to users and the public, but this was the first time in his career that he had gone before Congress. He also is to testify Wednesday before the House Energy and Commerce Committee.

In the hearings, Zuckerberg is not only trying to restore public trust in his company but also to stave off federal regulations that some lawmakers have floated. In his opening statement to senators, he also apologized for fake news, hate speech, a lack of data privacy and Russian social media interference in the 2016 elections.

“We didn’t take a broad enough view of our responsibility, and that was a big mistake,” he said. “It was my mistake, and I’m sorry. I started Facebook, I run it, and I’m responsible for what happens here.”

WATCH LIVE: Facebook CEO Mark Zuckerberg testifies before Senate committee

Separately, the company also began alerting users that their data was gathered by Cambridge Analytica. A notification that appeared on Facebook for some users Tuesday told them that “one of your friends” used Facebook to log into a now-banned personality quiz app called “This Is Your Digital Life.” The notice says the app misused the information, including public profiles, page likes, birthdays and current cities, by sharing it with Cambridge Analytica.

After resisting previous calls to testify, Zuckerberg agreed to come to Capitol Hill this month after reports surfaced — and the company confirmed — that Cambridge Analytica had gathered Facebook users’ data. Zuckerberg said his company has a responsibility to make sure what happened with Cambridge Analytica doesn’t happen again.

Zuckerberg is also expected to be asked about Russia’s use of U.S. social media during the 2016 elections — a subject of several congressional investigations and special counsel Robert Mueller’s probe into Russian interference.

In his opening statement, Zuckerberg addressed Russian election interference and acknowledged, as he has in the past, that the company was too slow to respond and that it’s “working hard to get better.” The company has said that as many as 146 million people may have received information from a Russian agency that’s accused of orchestrating much of the cyber meddling in the election.

“We will continue working with the government to understand the full extent of Russian interference, and we will do our part not only to ensure the integrity of free and fair elections around the world, but also to give everyone a voice and to be a force for good in democracy everywhere,” Zuckerberg continued.

In the testimony, Zuckerberg acknowledged that the questioning could be hostile.

“We face a number of important issues around privacy, safety, and democracy, and you will rightfully have some hard questions for me to answer,” Zuckerberg said.

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Associated Press writer Lisa Mascaro contributed to this report. Ortutay reported from New York.

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