In mid-March The New York Times, along with The Guardian and The Observer, reported that Cambridge Analytica and its British counterpart SCL had harvested the data of 50 million Facebook users through an app called thisisyourdigitallife, which offered personality quizzes.
This information was used to target voters in the U.S., based on psychological profiling, with political adverts spreading disinformation.
They've also led to calls for Zuckerberg's resignation.
"In that case, our systems detect what's going on", Zuckerberg said. "We need to know how they are going to fix this problem next week at our hearing".
Facebook last week said it is also shutting down access to data brokers who use their own data to target customers on Facebook.
Later addressing the impact that restricting ad targeting on the network may have on the business side of the platform, he added: "I just think it would be near-sighted to focus on short-term revenue over what value to people, and I don't think we're that short-sighted".
Users are able to flag posts or messages that they feel are in violation of the site's house rules.
"Facebook designed these automated tools so we can rapidly stop abusive behaviour on our platform".
Zuckerberg, who previously struggled to articulate his position on privacy, said the company will boost employees devoted to security to about 20,000 by the end of the year as well as be open to comply with Europe's strict General Data Protection Regulation privacy regulations everywhere. For more on this read the full USA Today report here. "If we can't, we don't deserve it". It will also prevent apps from using Facebook Login to collect users' personal information, including details like their religious or political views, relationship status, education and work history, and more.
"Not that I'm aware of", he said and then moved on to the next question. We're now taking steps to make sure this doesn't happen again.
"Facebook was stating 's hey were not sharing data with advertisers", Derigiotis said. The company plans on reducing the amount of usage developers have access to. Or, at least that's what he told us.
The news served as a hefty warning to marketers on the importance of transparency with consumers about how their information is used, and more stringent governance practices around access, and usage.
The apology was formally signed off by the Facebook chief.
You can imagine farms of shady data collection firms typing in your mother's phone number, finding her Facebook profile and sucking into its databases more information about her favorite TV shows, home town and political affiliations. Posts and other content set to be visible only to friends weren't collected.
Australians made up one in every 250 accounts accessed.
Zuckerberg's announced testimony before House Energy and Commerce is his first confirmed appearance ever in front of a congressional committee, although a Facebook spokesperson told ABC News that "conversations with other committees continue" about additional appearances on Capitol Hill.
"They have plundered my phone".
Schroepfer said until now, people could grant an app permission to get information about events they host or attend, including private events.
"Contact uploading is optional".
In particular, the days where you could inadvertently give apps information on your Facebook friends are over.