Facebook has confirmed that it has started scoring some of its members on a trustworthiness scale.
The Washington Post revealed that the social network had developed the system over the past year.
The tech firm says it has been developed to help handle reports of false news on its platform, but it has declined to reveal how the score is calculated or the limits of its use.
Critics are concerned that users have no apparent way to obtain their rating.
The BBC understands that at present only Facebook’s misinformation team makes use of the measurement.
The tech firm has, however, objected to the tool being described as a reputation rating.
“The idea that we have a centralised ‘reputation’ score for people that use Facebook is just plain wrong and the headline in the Washington Post is misleading,” said a spokeswoman.
“What we’re actually doing: We developed a process to protect against people indiscriminately flagging news as fake and attempting to game the system.
“The reason we do this is to make sure that our fight against misinformation is as effective as possible.”