Facebook's shares has lost billions of dollars in value after something to do with data used by Cambridge Analytica.
Confused? Here's what it means, and what could come next.
Cambridge Analytica is a London-based consulting firm. It is under pressure over allegations it uses illegally obtained data
and social media manipulation to influence elections.
Those claims come from Christopher Wylie, 28, who told The Guardian he helped found the company and that he came up with the technique
which combined psychological profiling and information warfare.
In a nutshell, there's three main points to Mr Wylie's story:
• People were targeted with political ads individually tailored to their personality to manipulate them to get them to vote for Donald Trump in the 2016 election
• The data was obtained via a personality test on Facebook and pulled in information about what their friends liked without their explicit permission
• The same technique has potentially been applied to elections across the world, with the company selling its services to the highest bidder
Mr Wylie said the data was collected very quickly. About 320,000 people used the personality quiz app on Facebook
"thisismydigitallife" created by Global Science Research (GSR), run by Cambridge-based academic Aleksandr Kogan.
Mr Wylie said the data of about 50 million users was harvested in about two months by accessing those users' friends
He also said the name Cambridge Analytica had nothing to do with the Cambridge University in the UK, other than it had
an office in the town and intentionally used the name to seem more authoritative.
The claims have led to investigations in the UK, the US
and the EU.
Click a link to play audio (or right-click to download) in either
UK Information Commissioner Elizabeth Denham has said she would apply for a warrant to search Cambridge Analytica
offices, and the head of the UK's inquiry into fake news has requested Facebook boss Mark Zuckerberg give answers about
Facebook having previously misled it.
Mr Wylie has submitted evidence to the UK's Information Commissioner's Office and its National Crime Agency's cybercrime
unit, The Guardian reported.
• Here's The Guardian's detailed write-up
of the Christopher Wylie whistleblowing, with an explanatory video interview
• Here is RNZ Insight's documentary
exploring Cambridge Analytica, and social media use ahead of New Zealand's election last year
One of Mr Trump's campaign backers, secretive US hedge-fund billionaire and Republican donor Robert Mercer, was
Cambridge Analytica's main investor after former Trump campaign head Steve Bannon brought the firm - including Mr Wylie
- to pitch to him.
For its part, Cambridge Analytica has denied any wrongdoing. The firm insisted it followed the correct procedures in
obtaining and using data.
Why it matters
The question now is whether what Cambridge Analytica and Facebook have each done is actually illegal, and what parts of
it may just be considered immoral.
Initially objectionable is the way the GSR data - which Mr Wylie says has essentially formed the basis for Cambridge
Analytica's work - was obtained.
Further concerns surround the effect on democratic elections. Certainly, there has been spin in political elections
forever, but putting the ability to sway public opinion into the hands of those who can pay would seem to undermine the
very basis of democracy.
Mr Wylie told The Guardian the company was willing to subvert elections on behalf of foreign governments. He also claimed a Russian oil company was
fully briefed by the company about how it uses personality data to affect elections.
Facebook shares have plummeted since the story broke, dropping 6.7 percent of its value on Monday, wiping almost $37bn
from its market value.
Mr Wylie told The Guardian no one at Cambridge Analytica had checked if taking the data was legal. The GSR app that was taking the data apparently
had permission to do so for "academic purposes only".
Mr Wylie claims to have a contract between GSR and Cambridge Analytica's parent company specifically for harvesting and
processing Facebook data.
A report in 2015
claimed the firm was using Facebook data to support US Republican Ted Cruz.
Mr Wylie said the only effort Facebook made to retrieve the data after the 2015 report was to send him a letter - months
later in August 2016, some two years after the breach took place and after he had left Cambridge Analytica - saying the
data had been illicitly obtained and GSR "was not authorised to share or sell it".
Mr Wylie said the letter asked the data to be deleted immediately, tick a box saying it had been done, and send the
letter back to Facebook.
Cambridge Analytica was suspended from Facebook on Saturday, making it harder for the company to carry out its role.
In a statement
, it said it fully complied with Facebook's terms of service and did not hold data from Facebook profiles.
"Global Science Research (GSR), was contractually committed by us to only obtain data in accordance with the UK Data
Protection Act and to seek the informed consent of each respondent. GSR was also contractually the Data Controller (as
per Section 1(1) of the Data Protection Act) for any collected data. GSR obtained Facebook data via an API provided by
Facebook," it said.
"When it subsequently became clear that the data had not been obtained by GSR in line with Facebook's terms of service,
Cambridge Analytica deleted all data received from GSR."
Mr Wylie said there were multiple copies of the data, however, and it had been emailed in unencrypted files.
What Cambridge Analytica says
Cambridge Analytica has now suspended its chief executive Alexander Nix
over comments secretly recorded by the UK's Channel 4, "pending a full, independent investigation".
"We did all the research [for the Trump campaign].
"We did all the data. We did all the analytics. We did all the targeting. We ran all the digital campaign and our data
informed their strategy," Mr Nix told an undercover reporter during a meeting in a London hotel.
Mr Nix also said he had met the then Republican presidential candidate Donald Trump "many times" and that his firm
played a central role in the final months of the campaign.
Before his suspension, Cambridge Analytica claimed
Facebook data from GSR had all been deleted, and was not used for Donald Trump's campaign.
It also put out a statement
saying the interview was mischaracterised and obtained through entrapment.
"Assessing the legality and reputational risks associated with new projects is critical for us, and we routinely
undertake conversations with prospective clients to try to tease out any unethical or illegal intentions. The two
Cambridge Analytica executives at the meeting humoured these questions and actively encouraged the prospective client to
disclose his intentions. They left with grave concerns and did not meet with him again," the statement said.
How to protect your data on Facebook
There are a few things to be aware of if you want to restrict who has access to your data.
• Keep an eye on apps, especially those which require you to log in using your Facebook account - they often have a very
wide range of permissions and many are specifically designed to pick up your data
• Use an ad blocker to limit advertising
• Look at your Facebook security settings and make sure you are aware of what is enabled. Check the individual app
settings to see whether you have given them permission to view your friends as well as yourself
• You can download a copy of the data Facebook holds on you, although it is not comprehensive. There is a download
button at the bottom of the General Account Settings tab. However, bear in mind that your data may be less secure
sitting on your laptop than it is on Facebook's servers if your device is hacked
• You can of course, simply leave Facebook, but the campaign group Privacy International warns that privacy concerns
extend beyond the social network