Facebook founder Mark Zuckerberg says he is sorry for what he has described "as a major breach of trust" over the Cambridge Analytica scandal, saying the social media platform failed in its "basic responsibility" to protect users' information.

Key points: Mark Zuckerberg says Facebook will do more to restrict developers who have misused data

Mark Zuckerberg says Facebook will do more to restrict developers who have misused data Statement comes as company is in crisis mode amid a #DeleteFacebook movement

Statement comes as company is in crisis mode amid a #DeleteFacebook movement Man who created the app that was used to mine data says he's been made a "scapegoat"

He told CNN during an interview that his company would take steps to make sure it does not happen again, primarily by ensuring app developers do not get as much access to users' information, and making sure there "aren't any other Cambridge Analyticas out there".

He said Facebook would also create a tool that would allow users to learn if they might have been affected by the scandal, which involves allegations that an app developer improperly obtained and kept user data after telling the social media giant it had been deleted.

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Mr Zuckerberg said Facebook would also look back years to see where other breaches might have occurred.

"Well, it's hard to know what we'll find, but we're going to review thousands of apps," he said.

"This is going to be an intensive process, but this is important; I mean this is something that, in retrospect, we clearly should have done, upfront, and we're not going to make that mistake again."

In the interview, Mr Zuckerberg defended Facebook's handling of the situation since the allegations first came to light.

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He said after Facebook heard reports Cambridge Analytica had the data, it immediately banned the app and asked for formal certification it had deleted, or no longer had, the data.

"I'm used to when people legally say they are going to do something that they do it," he said.

Mr Zuckerberg also discussed other failings, saying Facebook had not previously done as much as it should have to prevent its platform being used for fake news and foreign interference in the 2016 US presidential election.

He said he was "sure" there were people seeking to use Facebook again to interfere in the US mid-term elections and others around the world.

He said such interference mainly came in the form people working to "sow division", often creating rival political groups.

Mr Zuckerberg admitted he would have been surprised if, when he first started Facebook, he was told he would eventually be responsible for trying to prevent fake news and foreign interference in elections.

Stricter rules for app developers

In his first statement on Cambridge Analytica this morning, Mr Zuckerberg said Facebook would impose stricter rules on developers of third-party apps that collect your data, and will create a new section in your News Feed where you can review those that you use.

"There's more to do, and we need to step up and do it," he said.

Facebook suspended London-based political research company Cambridge Analytica last week over the scandal.

The data was reportedly collected by University of Cambridge psychology academic Aleksandr Kogan via a survey app on Facebook years ago, and then passed onto Cambridge Analytica, which used it to target people with political advertising during the 2016 US election campaign.

Only 300,000 Facebook users responded to Mr Kogan's quiz, but that gave him access to those people's friends as well, who had not agreed to share information, producing details on 50 million users.

"This was a breach of trust between Kogan, Cambridge Analytica and Facebook," Mr Zuckerberg said.

"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."

So what is Facebook going to do about it?

Mr Zuckerberg has announced that Facebook will now:

Create a new section at the top of your News Feed that will show you the apps you've used and allow you to revoke their permissions

Create a new section at the top of your News Feed that will show you the apps you've used and allow you to revoke their permissions Reduce the amount of data that you give an app when you sign in to only your name, profile photo and email address

Reduce the amount of data that you give an app when you sign in to only your name, profile photo and email address Automatically revoke developers' access to your data if you don't use their app for three months

Automatically revoke developers' access to your data if you don't use their app for three months Investigate all third-party apps that collected large amounts of data before 2014 (when it imposed restrictions on how much they could access) and conduct full audits on any that show suspicious activity

Investigate all third-party apps that collected large amounts of data before 2014 (when it imposed restrictions on how much they could access) and conduct full audits on any that show suspicious activity Identify any developers who have misused information and inform you if you've used their apps

Identify any developers who have misused information and inform you if you've used their apps Require developers to get approval before accessing your posts and private data

Facebook is in crisis mode

Mr Zuckerberg is facing growing calls to appear before a British parliamentary inquiry into the breach, and has been in crisis mode since a #DeleteFacebook movement spawned on Twitter.

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Since the allegations were published at the weekend, the company has lost more than $US45 billion of its stock market value and analysts say its relationship with advertisers may be in trouble.

"While this specific issue involving Cambridge Analytica should no longer happen with new apps today, that doesn't change what happened in the past," he said.

"We will learn from this experience to secure our platform further and make our community safer for everyone going forward."

What has Cambridge Analytica said?

Sorry, this video has expired Fmr Cambridge Analytica employee blows whistle on Facebook fake news

On Tuesday, the board of Cambridge Analytica suspended its chief executive officer Alexander Nix, who was caught in a secret recording boasting that his company played a decisive role in Mr Trump's victory.

But Mr Kogan disputed that in an interview with the BBC on Wednesday.

"I think what Cambridge Analytica has tried to sell is magic, and they've made claims that this is incredibly accurate and it tells you everything there is to tell about you. But I think the reality is it's not that," he said.

Mr Kogan said that he was being made a scapegoat by Facebook and Cambridge Analytica, as both companies have blamed him for the alleged data misuse.

ABC/Reuters