NEW DELHI: Facebook CEO Mark Zuckerberg broke his five-day silence on Cambridge Analytica data breach on Thursday and admitted that his company "made mistakes" and a "breach of trust" had occurred between it and its users.

Zuckerberg first shared a Facebook post admitting the social media platform's mistake and then appeared on CNN over his company's biggest-ever controversy.

"This was a major breach of trust, and I'm really sorry that this happened. We have a basic responsibility to protect people's data and if we can't do that then we don't deserve to have the opportunity to serve people," Zuckerberg told CNN.

In an interview to the channel, he said now his responsibility is to "make sure this doesn't happen again". To prevent such a breach, Zuckerberg said, Facebook is "doing a set of things to restrict the amount of access that developers get going forward".

"We need to make sure there aren't any other 'Cambridge Analyticas' out there", he said adding that Facebook will now investigate every application that has access to a large amount of user data.

He also vowed to initiate a "full forensic audit" in case Facebook finds any other application retaining improperly obtained information.

The CEO told CNN the Facebook will proactively reach out and notify "anyone whose data might have been affected" by any third party application. "We are going to build a tool where anyone can go and see if their data was a part of this," he said.

Facebook is facing the heat after Cambridge Analytica, a British consulting company, was accused of harvesting data of up to 50 million Facebook users without permission and using the data to help politicians, including US President Donald Trump and the Brexit campaign.

Earlier on Thursday, Zuckerberg in a Facebook post said: "I want to share an update on the Cambridge Analytica situation -- including the steps we have already taken and our next steps to address this important issue. I've been working to understand exactly what happened and how to make sure this doesn't happen again.."

"The good news is that the most important actions to prevent this from happening again today we have already taken years ago. But we also made mistakes, there's more to do, and we need to step up and do it," he added.

He said Facebook would restrict developers' data access even further to prevent other kinds of abuse.

"...We want to make sure you understand which apps you've allowed to access your data. In the next month, we will show everyone a tool at the top of your News Feed with the apps you've used and an easy way to revoke those apps' permissions to your data. We already have a tool to do this in your privacy settings, and now we will put this tool at the top of your News Feed to make sure everyone sees it."

In his post, Zuckerberg gave a timeline of events that happened since the inception of the platform, saying there is a need to do more.



"This was a breach of trust between Kogan, Cambridge Analytica and Facebook. But it was also a breach of trust between Facebook and the people who share their data with us and expect us to protect it. We need to fix that," he wrote.

The company would investigate all apps that had access to large amounts of information before it changed the platform to dramatically reduce data access in 2014 and conduct a full audit of any app with suspicious activity.

"We will ban any developer from our platform that does not agree to a thorough audit. And if we find developers that misused personally identifiable information, we will ban them and tell everyone affected by those apps," he said.

Facebook's chief operating officer, Sheryl Sandberg, shared Zuckerberg's post and added her own comment: "We know that this was a major violation of people's trust, and I deeply regret that we didn't do enough to deal with it. We have a responsibility to protect your data - and if we can't, then we don't deserve to serve you".

"We've spent the past few days working to get a fuller picture so we can stop this from happening again."

"If we find that developers misused personally identifiable information, we'll ban them from our platform and we'll tell the people who were affected," she wrote.

"You deserve to have your information protected - and we'll keep working to make sure you feel safe on Facebook. Your trust is at the core of our service. We know that and we will work to earn it," she said.