Italy's competition authority has handed Facebook two fines totaling 10 million euros ($11.3 million).
Facebook “misleadingly gets people to sign up… without informing them in an immediate and adequate way of how the data they will provide will be harvested for commercial purposes,” a statement from Italy's AGCM consumer and market watchdog said today.
It also said Facebook uses unfair practices over the transmission of users' data to third-party apps and sites.
The company also does not clearly tell people about “the remunerative purpose that underlies the provision of the social network's services, simply stressing the fact that it's free.”
Facebook “aggressively” discourages users from trying to limit how the company shares their data by telling them that by doing so they risk “significant limitations”.
It says Facebook is now obliged to publish a “corrective statement” to all users via its desktop site and apps.
The fines were the result of an investigation Italy opened in April this year.
And this comes just two weeks after Facebook Italy agreed to “make a payment of more than 100 million euros” to end a fiscal fraud dispute with Italian authorities.
The data at the centre of the controversy was obtained from a personality quiz app downloaded by some 300,000 people. It gathered details about their Facebook friends without their knowledge, permitted by Facebook's rules at the time.
Reports suggest the data was then used by Cambridge Analytica as part of its work on Donald Trump's 2016 presidential campaign, though the British firm denies this.
Facebook has been hit by several scandals this year starting with the Cambridge Analytica revelations in March.
Facebook has repeatedly said it does not sell users' data.
The company said in a statement that it's reviewing the Competition Authority's decision and hopes to work with the agency to resolve its concerns.
The company has faced a barrage of criticism recently for the misuse of users' data to influence elections amid increasing calls for the company run by Mark Zuckerberg to be regulated.