Facebook paid outside contractors to transcribe recorded audio clips of the company’s users, Bloomberg reported Tuesday. The contractors were reportedly not told where the audio was recorded, how it was obtained, or why Facebook needed user conversations transcribed—some of which contained “vulgar content.”

Facebook confirmed to Bloomberg that it had been transcribing the user audio but would stop the practice. “We paused human review of audio more than a week ago,” the company said Tuesday, adding that those affected were users who chose to have their voice chats transcribed in Facebook’s Messenger app.

According to the company, the contractors were checking if artificial intelligence were correctly transcribing the anonymized messages. However, Facebook reportedly did not inform users that their conversations could potentially be reviewed by a third-party. This comes after Facebook agreed to pay $5 billion fine to the FTC as part of a settlement related to an investigation into the company’s privacy violations.