Facebook CEO Mark Zuckerberg took an apologetic tone in a call with reporters Wednesday afternoon, weeks after the Cambridge Analytica debacle that has put a new level of pressure on the social media giant.

"We didn't think about how people could use these tools for harm as well," Zuckerberg said.

The call, which lasted nearly an hour, came just after the company's chief technology officer issued a lengthy statement outlining numerous changes the company is making in the name of privacy and information security. Facebook is also updating its privacy policy.

Notably, Zuckerberg said that Facebook will voluntarily implement the European Union's new privacy rules, known as the GDPR, which take effect in May 2018. "We're going to make all the same controls and settings available everywhere, not just in Europe," he said.

Last month, news broke that the British data analytics contractor Cambridge Analytica, which worked with Donald Trump's presidential campaign, retained private data from 50 million Facebook users despite claiming to have deleted it. The scandal has spawned numerous lawsuits, and it has put significant pressure on Cambridge Analytica and Facebook.

Cambridge Analytica and its affiliate companies have claimed that they did nothing wrong. The company's London offices were raided on March 23 by local investigators.

In fact, during the call, Cambridge Analytica again professed its innocence.

When Facebook contacted us to let us know the data had been improperly obtained, we immediately deleted the raw data from our file server, and began the process of searching for and removing any of its derivatives in our system. — Cambridge Analytica (@CamAnalytica) April 4, 2018

Zuckerberg said that Facebook was founded on a sense of idealism but that those original assumptions have recently been tempered somewhat.

"We didn't take a broad enough view of what our responsibility is," Zuckerberg said. "It was a huge mistake. It was my mistake. It's not enough to just connect people. We have to make sure that those connections are positive and bringing people together. It's not enough to give people tools. It's not enough to have rules that they protect information—we have to ensure that everyone in our ecosystem protects people's information. We're broadening our view of our responsibility. It's on us to make sure those tools are used well."

Facebook has been attempting to revamp its privacy policies and reassure the public, regulators, and lawmakers that it is taking the crisis seriously. Zuckerberg is expected to testify before Congress next week.

Zuckerberg added that there are currently 15,000 people working on "security and content review," with 20,000 expected by the end of the year. The CEO also said that he had not fired anyone as a result of the Cambridge Analytica situation. "At the end of the day, this is my responsibility," he said, telling other reporters that, nevertheless, he did feel that he was the one best suited to hold the company's top job.

He also admitted that Facebook needs to "do a better job of explaining what we actually do," adding that "the vast majority of the data that Facebook knows about you is because you chose to share it."

Zuckerberg specifically said the company did not "track" its users or "buy and sell" user data.

"We run ads to make it a free service that everyone in the world can afford," he said.

Ars sent Facebook a short list of questions that we would have asked while on the phone with Zuckerberg had we been given the chance, but the company did not immediately respond.