Facebook did nothing to alert its users two years ago about a massive data breach of 50million accounts on it's platform by Cambridge Analytica.

After Facebook learned about profiles that were harvested in 2014 by the political data firm, Cambridge Analytica, the social network sent a letter in 2016 to Christopher Wylie, who has since left the firm, to delete the user data it acquired.

Facebook's lawyer's letter said the data had been illicitly obtained and it must be deleted immediately.

'I already had. But literally all I had to do was tick a box and sign it and send it back, and that was it,' says Wylie. 'Facebook made zero effort to get the data back.'

Full Facebook statement regarding Cambridge Analytica below

CEO of Cambridge Analytica Alexander Nix (pictured) was involved in acquiring the data for his company's various applications including electoral profiling

Whistleblower: Christopher Wylie (pictured) has come forward after a year of legal hurdles to discuss with the Guardian how he aided in acquiring Facebook profiles and data of Americans

Facebook has released a statement denying that the data from their 50million users was breached

The Guardian reporter Carole Cadwalladr, who broke the bombshell story on Saturday, told CBSN that Facebook threatened to sue her publication in a bid to prevent their exposé on its users' data being harvested from being published.

Cadwalladr says she believes Facebook failed to inform users their data was being misused because it wasn't in the company's best interest.

'This continual pattern that we've seen with Facebook - trying to shut the story down, finally when it has no choice, acknowledge it. They've just really got to do better,' she said.

'What we desperately need is for Facebook to finally open up and be as honest and transparent as it can be about the way that their platform was used and manipulated during the U.S. presidential elections, during Brexit in the U.K.,' Cadwalladr said.

Facebook released a statement on Friday acknowledging that it learned it had been 'lied to' about Cambridge Analytica and an affiliate's activities in 2015, more than two years before suspending the firm from its platform, but did not alert users at the time.

Yet, Facebook insisted there was no breach of their system.

After speaking with the U.K. Information Commissioner's Office, which promotes the protection of private information, Cadwalladr said it is clear 'this is a data breach.'

'Facebook has just turned around and blamed a third party,' Cadwalladr said. 'We are clear this is a data breach, and Facebook's denials in the face of it - their claim that it's not a data breach because nobody hacked into their system - well, failing to secure your own data, failing to see how it's being used ... that falls within the definition of a data breach. Accept it, Facebook. Own it.'

'In a way it's even more damning that [Cambridge Analytica] got all of this data from Facebook without it being a breach,' Wired editor-in-chief and CBS News contributor Nick Thompson said on CBSN.

'It didn't work because somebody hacked in and broke stuff,' Thompson added. 'It worked because Facebook has built the craziest most invasive advertising model in the history of the world and someone took advantage of it.'

Cadwalladr said Facebook would have needed to inform 58 million people that their personal information was taken and 'essentially, there's no way of getting it back.'

'Once it's taken, it's out in the world, it can be copied, it can be stored elsewhere -- we just don't know what's happened to that data,' Cadwalladr said Saturday. She said she was appalled that Facebook did 'almost nothing' to delete or secure the data that was harvested.

At the heart of the issue is that a Facebook compatible app by Global Science Research called Thisisyourdigitallife, was granted access to Facebook users, and it was permitted by the platform by Facebook.

The app is the brainchild of Cambridge-based academic Aleksandr Kogan.

While Steve Bannon was at Breitbart News, he became acquainted with Cambridge Analytica and continued working with the firm while he was Trump's campaign strategist

Cambridge Analytica had ties with the Trump campaign during the 2016 presidential election

The information that was gathered by Thisisyourdigitallife was then sold to Cambridge Analytica, and users who agreed to their info being used under the app, did not permit it to be used for political psycho-analytics.

This wasn't the first incident that Facebook was made aware of Cambridge Analytica utilizing Facebook user data in ways the user, nor Facebook, agreed to.

In December 2015, The Guardian published its very first report about Cambridge Analytica using acquiring Facebook data to support Ted Cruz in his campaign to be the US Republican candidate.

Again Facebook was slow in a response.

Several months later Facebook took action and again it was in the form of a letter.

Meanwhile, Wylie's admissions in the Guardian report have been staggering. 'We 'broke' Facebook,' he says.

'Is it fair to say you 'hacked' Facebook?' I ask him one night, asked the Guardian's Cadwalladr in her shocking Saturday expose.

He hesitates. 'I'll point out that I assumed it was entirely legal and above board.'