Facebook has collected personal data from its users in Spain without obtaining their "unequivocal consent" and without informing them how such information would be used, the Spanish Data Protection Agency said in a statement.
"Facebook collects data on ideology, sex, religious beliefs, personal tastes or navigation without clearly informing about the use and purpose that it will give them," the statement said.
The agency said Facebook did not remove the personal data which it collects from its data base even when a user requests this.
It said it fined the company 600,000 euros for a very serious violation of the country's data protection rules and 300,000 euros each for two serious violations.
The 1.2-million-euro fine is small in the context of the company which posted advertising revenues of $9.2 billion in the second quarter, mainly from mobile video ad sales.
Contacted by AFP, Facebook was not immediately available to react to the fine.
It is the latest in a series of legal problems that have beset the social networking giant in recent years.
France's data protection agency in May fined Facebook €150,000 for failing to prevent its users' data being accessed by advertisers following a two-year investigation.
It said at the time that Facebook had built up "a massive compilation of personal data of internet users in order to display targeted advertising".
Last year French watchdog had given Facebook a deadline last year to stop tracking non-users' web activity without their consent and ordered the social network to cease some transfers of personal data to the United States.
Belgian, German, and Dutch governments are also looking into how Facebook holds and uses data pertaining to their citizens, according to Spain's data protection agency.
A "contact group" has been formed at the European level to protect that personal data of Facebook users which is made up of the Spanish data protection agency and its counterparts in France, Belgium, Germany and the Netherlands.
Facebook's social network, now with 2.01 billion monthly active users, is steadily driving sales at a faster pace than other technology giants.