For a situation brought by Belgium's protection guard dog, the court additionally decided that Facebook needed to erase all information it had assembled unlawfully on Belgian subjects, including individuals who were not Facebook clients.
A Belgian court threatened Facebook (FB.O) on Friday with a fine of up to 100 million euros ($125 million) if it continued to break privacy laws by tracking people on third-party websites.
According to the court, besides tracking unregistered users who click "like" or "share" buttons on Facebook pages, even when they have no registered account, Facebook also tracks visitors of roughly 10,000 third-party websites via invisible pixels put on those sites.
Facebook has said it is disappointed with the current verdict and will appeal.
Echoing the privacy watchdog's conclusions, it said that the social network does not properly inform people about the fact it is gathering information about them.
"Facebook must also destroy all personal data obtained illegally", the court ordered.
Jeremy Corbyn never knowingly met communist spy, says Czech agency
Jeremy Corbyn has dismissed claims that he met and briefed a Czech spy during the Cold War years as a "ridiculous smear". Corbyn's team called the story a "smear" and commented: "Like other MPs, Jeremy has met diplomats from many countries".
"We hope they will now make this a reality".
"We've built teams of people who focus on the protection of privacy - from engineers to designers - and tools that give people choice and control", it said.
It said the cookies and pixels it uses are "industry standard technologies", allowing hundreds of thousands of businesses to grow and reach their customers.
"Too much uncertainty about the nature of the information it collects, what happens to that information and how long the company stores that information". It has been ordered to delete all the data tit has collected by using cookies.
It has found Facebook and Twitter wanting in aligning their terms of services with European Union consumer protection rules.
"We'll consent to this new law, similarly as we've agreed to existing information security law in Europe", Facebook's VP of open approach for Europe Richard Allan said.