Facebook founder Mark Zuckerberg spent more than four hours being grilled by members of US Congress on day one of his senate hearing, answering questions about digital privacy in wake of the Cambridge Analytica scandal.
The CEO announced plans to audit every single app used within the platform, to ensure the personal data of users is not compromised by third-party apps, the way it was by the political firm.
More than 87 million users' accounts were accessed by Cambridge Analytica, including more than 300,000 in Australia.
Zuckerberg has admitted that they didn't do enough to make sure the firm had deleted the information they improperly obtained back in 2015.
"They told us that they did [delete the data] this. In retrospect, it was clearly a mistake to believe them. We should have followed up and done a full audit then... we have updated our policies to make sure that we don't make that mistake again," Zuckerberg said during the hearing.
One comment that sparked much interest was Zuckerberg presumably suggesting that a paid, ad-free version of the social media platform could be a possibility in the future, which would give users an option to stop their information being shared with advertisers.
Zuckerberg didn't deny the company was looking at a paid option, but emphasized that there will "always be a version of Facebook that is free".
"To be clear, we don't offer an option today for people to pay to not show ads. We think offering people an ad-supported service is the most aligned with our mission of trying to connect everyone in the world, because we want to offer a free service that everyone can afford. That's the only way we can reach billions of people."
Zuckerberg will reappear before congress tomorrow for the second and final day of his hearing.