Facebook has been hiring third-party contractors to review and transcribe audio clips of its users, according to a new report from Bloomberg. Facebook claims it stopped using human workers to review audio clips “more than a week ago,” noting that the contractors were previously hired to check whether anonymized conversations were being correctly transcribed on the Messenger app.

Since 2015, Messenger has offered a feature to transcribe voice clips to text, although it is turned off by default. Facebook claims only those who opted in to the feature had their audio clips reviewed by third-party contractors. However, according to its support page, if even one person in your chat has consented to Facebook transcribing the conversation, any audio in the thread would have been translated, regardless of who sent it.

The findings are particularly troubling given that nowhere in Facebook’s support page or terms of service does it indicate that humans would be reviewing the audio. “Voice to Text uses machine learning. The more you use this feature, the more Voice to Text can help you,” the support page reads.

Google, Apple, Microsoft, and Amazon have all allowed human contractors listen to users’ audio clips

“Facebook says its ‘systems automatically process content and communications you and others provide to analyze context and what’s in them.’ It includes no mention of other human beings screening the content,” Bloomberg’s Sarah Frier reports. Facebook also only identifies third-party vendors in its terms of service as providers who “support our business” by “analyzing how our products are used,” but it does not clearly spell out that this may include humans.

The report comes after it was found that Google, Apple, Microsoft, and Amazon all used human contractors to listen to audio obtained through their voice assistant products without being explicitly transparent with their users. Amazon has since allowed users to opt out, while Google defends its practice, claiming the process helps Google Assistant operate in multiple languages. Apple, on the other hand, announced last week that it has stopped using human contractors to review Siri conversations, and it will soon allow users to opt out.

While conspiracy theories about Facebook secretly listening to conversations have existed for years, it’s important to note that Bloomberg’s report is not claiming Facebook is actually doing that. The third-party contractors were allowed to listen to the audio that some users — in theory — gave permission for. Facebook just didn’t make clear to users exactly who was creating their transcriptions.