The FTC's five commissioners were split along party lines in green-lighting the deal, with the two Democrats reportedly pushing for not only a huge fine but some form of tough regulation to stop the same thing happening again and again and again.
The FTC is expected to include other government restrictions on how Facebook treats user privacy, WSJreported.
Markets have rewarded Facebook for getting off so lightly, covering the cost of the fine and adding another $5 billion to the company's coffers.
The investigation began after reports that a political consulting firm that worked with President Trump's campaign in 2016, Cambridge Analytica, had improperly obtained information on millions of Facebook users.
The New York Times reported that under the terms of the settlement, Facebook will be able to continue sharing data with third parties, but there will be more oversight into how it handles user data. In its latest financial report, Zuck & Co set aside $3bn in anticipation of an FTC smack-down, leaving the biz with $2.43bn in profit off $15bn of revenues from the first three months of the year.
Peter Kaplan, a spokesman for the FTC, declined to comment.
Although the fine has not been officially confirmed - and neither the FTC nor Facebook are commenting on the matter - a Friday vote on the fine is said to have gone 3-2 in favor of approving it.
The investigation sought to determine whether Facebook violated the terms of a 2011 consent decree it signed with the FTC, which restricted the ways it could share users' personal data. Already this year the company has shown that it continues to mishandle data (hello to all those user passwords stored in a readable format). That revelation prompted several others that eventually led to global scrutiny of Facebook's practices.
Even as it resolves the FTC privacy inquiry, Facebook is still grappling with regulatory scrutiny on several other fronts - including the prospect of a new investigation by the FTC's antitrust section.
Does that mean Facebook wants to be fined $5 billion a quarter through 2021? The revelation of this settlement may indicate that Facebook breached that agreement.
If the Justice Department approves the settlement-and it usually sides with the FTC on these matters-it would be the largest fine US regulators have ever issued a tech company. Nevertheless, its controls have remained leaky.