The social media giant generally tags users based on their behaviour on its platform for advertisers to select and target people interested in specific topics.
The labelling raises new concerns over data-driven profiling.
and targeting of users on the website, which has already faced criticism for the same tool algorithmically inferring information about users' race, sexuality and political views despite data protection legislation requiring explicit consent to hold such information.
The Danish Broadcasting Corporation first raised this problem with Facebook.
The issue at hand has "raised a number of important questions about the way Facebook's advertising systems work. Our goal is to ensure people see ads that are relevant and useful. It's better for the people using our service, as well as for advertisers," Facebook said in a statement.
"When we identify misuse of our ads products, we take action. Depending on the violation, we may remove the ad, suspend the ad account or even report the advertiser to law enforcement," it added.
In its 747-page response to questions raised by a US committee, Facebook said it had already ended partnerships with 38 of them with seven more due to expire in July and one more in October this year.
The UK's data protection watchdog also plans to slap a fine of 500,000 pounds ($662,501) on Facebook over the Cambridge Analytica data leak scandal. This is the highest permitted fine under Britain's data protection law.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)