Not even Facebook’s top dog was protected in the Cambridge Analytica scandal, a Senate committee has heard.

Mark Zuckerberg was again grilled by some of the United States top political figures for the second day of the joint committee.

The questions on the second day zeroed in on Facebook’s self-regulation and exposed the enormity of the data compromised in the recent Cambridge Analytica scandal.

When asked by Congresswoman Anna Eshoo if his personal data had been compromised, Zuckerberg simply replied “Yes.”

Eshoo continued to interrogate Zuckerberg on the affair, questioning whether he had taken immediate action once he learnt Cambridge Analytica’s 2015 quiz was “actually for targeted psychographic political campaign work.”

“When we learned in 2015 that a Cambridge University researcher associated with the academic institution that built an app that people chose to share their data with ... We got in touch with them, and we asked them to — to — we commanded that they delete any of the data that they had, and their chief data officer told us that they had.”

Despite this, it is now known that the data was not deleted and was in fact used to influence the 2016 presidential election campaign.

Is self-regulation enough?

Another topic discussed throughout the day was the regulation of Facebook.

Facebook was continually labelled by the respective Representatives as ‘self-regulated’, with almost all calling for the need for some form of governance.

Opening proceedings for the day, Chair of the Energy and Commerce Committee, Greg Walden, slammed the company’s operations in recent years and asked Zuckerberg for some clarity.

“While Facebook has certainly grown, I worry it may not have matured,” he said. “I think it's time to ask whether Facebook may have moved too fast and broken too many things.”

“What exactly is Facebook? Social platform? Data company? Advertising company? A media company? A common carrier in the information age? All of the above? Or something else?”

He also pointed out that Facebook had achieved its success “without having to ask permission from the federal government and with very little regulatory involvement.”

As calls for Facebook to move from self-regulation towards government control reverberated around the chamber, Zuckerberg made his views clear.

“The Internet is growing in importance around the world in people's lives, and I think that it is inevitable that there will need to be some regulation,” he said.

“So, my position is not that there should be no regulation. But I also think that you have to be careful about what regulation you put in place for a lot of the reasons that you're saying.”

He told the Committee that Facebook would soon be compliant globally to the European Union’s upcoming General Data Protection Regulation (GDPR) and claimed that “we've had a lot of these [GDPR] controls in place for years.”

Although Zuckerberg continually defended Facebook’s privacy controls, reminding the hearing that users at all times have the option to control who their posts are shared with and opt out of data being shared with advertisers, he did not seem overly willing to change anything.

When asked by Representative Frank Pallone Jr. whether he would change “all the user default settings to minimise, to the greatest extent possible, the collection and use of users' data?”, Zuckerberg responded, “Congressman, this is a complex issue that I think is — deserves more than a one-word answer.”

Shadow profiles

Perhaps the most notable admission from Zuckerberg during the second day of the inquiry was in regard to ‘shadow profiles’, or the collection of data from individuals who do not actually have a Facebook account.

When Zuckerberg was quizzed on the subject by Representative Ben Ray Lujan, he confirmed that Facebook did collect data of users who had not signed up with the social network, although he refused to use the term ‘shadow profiles.’

“Congressman, in general, we collect data of people who have not signed up for Facebook for security purposes, to prevent the kind of scraping that you were just referring to,” he said.

Lujan used this example to dispute Zuckerberg’s previous claims defending Facebook’s privacy controls.

“You said everyone controls their data, but you're collecting data on people that are not even Facebook users, that have never signed a consent, a privacy agreement — and you're collecting their data,” he said.