The UK's data privacy watchdog didn't mince words about Facebook's role in the Cambridge Analytica scandal: The social media giant "contravened the law by failing to safeguard" the information of 87 million people, it said.
The survey results were allegedly used by election consultants Cambridge Analytica to target voters in United States elections, including Donald Trump's presidential campaign. It is now estimated that a third-party app used by Cambridge Analytica to collect data from Facebook affected a total of 87m users around the world.
The report sets out regulatory action taken against a number of the star players in this year's data scandal, including a criminal prosecution against Cambridge Analytica's parent biz SCL Elections Ltd - which has since folded, in name at least - for failing to properly deal with the ICO's enforcement notice.
"We have been working closely with the Information Commissioner's Office in their investigation of Cambridge Analytica, just as we have with authorities in the USA and other countries", he added.
Analysts expect Facebook to make $22.6 billion in profit this year, according to FactSet.
Charity Privacy International said that regulators were getting tougher on Facebook.
ICO also called for an "ethical pause" of microtargeting ad tools to "allow the key players - government, parliament, regulators, political parties, online platforms and citizens - to reflect on their responsibilities in respect of the use of personal information in the era of big data before there is a greater expansion in the use of new technologies".
Facebook faces several other investigations, including others in Europe, a probe by the US Federal Trade Commission and, reportedly, several others at federal agencies such as the FBI and the Securities and Exchange Commission.
Mail.Ru told CNN it had not been contacted by Facebook about its investigation into the misuse of user data.
Without detailing how the information may have been used, it said the company had "failed to be transparent about how people's data was harvested by others". The watchdog believes that the Cambridge Analytica's affiliate companies may still retain some data, and steps need to be taken to ensure a complete cleanup.
Neither would be the first class action Facebook is fighting over this issue.
A leading litigation firm in the country filed a complaint with Australia's Information Commissioner, the country's privacy regulator, that could result in heavy fines for Facebook. The company has said it plans to do so "soon".
"We must change this fast as no-one should win elections using illegally obtained data", she said, adding: "We will now assess what can we do at the European Union level to make political advertising more transparent and our elections more secure".