WASHINGTON – A joint Senate committee pressed Facebook CEO Mark Zuckerberg on Tuesday about his company’s handling of user data after it was revealed that 87 million users had their data accessed by political consulting firm Cambridge Analytica without their consent.

In a five-hour marathon hearing that touched on a broad range of issues surrounding Facebook’s collection of user data, Colorado Republican Sen. Cory Gardner questioned a specific provision of the user privacy agreement that said Facebook could store user data after a user deleted his or her account “for a reasonable amount of time.”

Gardner asked Zuckerberg how long a period that was, but Zuckerberg said he wasn’t certain about the time frame.

“The intent is to get all the content out of the system as quickly as possible,” Zuckerberg said.

Gardner also discussed what he called an “expectation gap” between users and the company, which he described as a situation in which users don’t realize they are being tracked as they open news-feed links that open in a new tab or as they browse webpages with Facebook “like” buttons on them.

“I don’t think consumers and users necessarily understand that,” Gardner said. “You do need a lawyer to understand (the user agreement). I hope you can close that expectation gap by simplifying the user agreement.”

In his first appearance before a Congressional committee, Zuckerberg acknowledged that Facebook “didn’t do enough” to combat fake news, foreign interference in elections or protect data privacy, but he repeatedly emphasized that the company was committed to “getting it right.”

“We didn’t take a broad enough view of our responsibility, and that was a big mistake,” Zuckerberg said in his written statement. “It was my mistake, and I’m sorry.”

The Zuckerberg testimony comes after The New York Times and The Guardian revealed that Cambridge Analytica had received user data without user consent, raising privacy concerns about access to user information.

Zuckerberg testified that the company demanded that Cambridge Analytica stop using the data and delete it. The political consulting firm said it had deleted the data and Facebook then considered the matter a “closed case.”

In response to Cambridge Analytica’s use of user data, Zuckerberg outlined new steps the company will take to review and prevent other apps from accessing large quantities of Facebook user data.

Facebook will now allow apps to access only users’ names, profile pictures and email addresses. It will also end apps’ access to profile data if a user hasn’t used that app in three months.

Facebook, a platform with more than 2 billion users, is in the process of notifying users whose data was shared with Cambridge Analytica. Zuckerberg also said the platform is investigating apps that had access to user data before 2014, the year Facebook implemented new privacy safeguards.

If a forensic audit finds that an app was improperly using data, then Facebook will ban the application from the platform.

Senators also pressed Zuckerberg on Russian interference in the 2016 election after it was discovered that the Internet Research Agency, a Russia-based “troll farm,” used the platform for a disinformation campaign.

“One of my greatest regrets in running the company is that we were slow in identifying the Russian information operation in 2016,” Zuckerberg said.

Zuckerberg’s written testimony said Facebook found 470 IRA-linked accounts and pages, which created 80,000 posts over two years. He said the IRA reached 126 million accounts.

Facebook will now require that all political advertisers confirm their identity and location. Facebook will also identify political advertisers as such on the news feed.

“We need to take a more proactive role and a broader view of our responsibility,” Zuckerberg said. “It’s not enough to just build tools. We need to make sure that they’re used for good and that means that we need to now take a more active view in policing the ecosystem.”

Zuckerberg pointed to recent successes in removing fake accounts during recent elections in France, Germany and a special Senate election in Alabama. Zuckerberg credited the improvement with new artificial intelligence tools that weed out fake accounts.

Using these tools to prevent interference in the 2018 midterms, Zuckerberg said, is “one of my top priorities.”

“At the end of the day, this is going to be something where people measure us by our results,” Zuckerberg said. “I’m committed to getting this right.”

Andrew Eversden is an intern for The Durango Herald and a student at American University in Washington, D.C.