Facebook and Britain's Information Commissioner's Office is still investigating the Cambridge Analytica brief. However, this meant that the Facebook Events data would also include information about who else attended the event, as well as any posts shared on the event's wall.
"How can consumers have control over their data when Facebook does not have control over the data?" asked Representative Frank Pallone of New Jersey, the ranking Democrat on the House Energy and Commerce Committee, at the beginning of Wednesday's hearing. There are multiple articles showing you how to change your privacy settings and even delete Facebook altogether.
"If you're logged into Facebook and visit a website with the Like button, your browser sends us information about your visit", Facebook says.
Lawmakers were at times aggressive Tuesday as they accused Zuckerberg of failing to protect the personal information of millions of Americans from Russians intent on upsetting the USA election.
In both hearings before the Senate, Zuckerberg only mentioned two kinds of data: the information that people decide to share on the platform, and the data that is automatically collected about people's behavior.
Its stock is down about seven percent this year and, ironically, shares hit an all-time high just before the Cambridge Analytica scandal hit, but they've been down 16 percent ever since.
And Mark Zuckerberg added: "A number of people suggest that we should offer a version where people cannot have ads if they pay a monthly subscription, and certainly we consider ideas like that. I'm aware that there may be, but we are working with them". "And in the future, only apps we approve that agree to strict requirements will be allowed to use the Events API", said Schroepfer.
Eighty-seven percent of adults use Facebook or one of its products like photo-sharing app Instagram or chat app WhatsApp.
Zuckerberg said he believes the company collects "different data for those" and would follow up with further details - a line he frequently fell back on when he didn't provide a direct answer.
But clearly, their technical expertise leaves much to be desired, that we can't take their digital literacy for granted (that's why they have advisors who, one would hope, know a bit more). "It was my mistake, and I'm sorry", Zuckerberg said in his written testimony released by the US Congress.
Zuckerberg told lawmakers that Facebook had now removed the option for advertisers to exclude ethnic groups from targeting.
"We don't sell the data".
The University's School of Information has been studying the implications of Facebook and the information infrastructure for almost a decade, said information studies professor Andrew Dillon. For most of our existence, we focused on all of the good that connecting people can do.
Investors in other social media stocks are enjoying a bump too.