Facebook has been listening to users' voice messages without their knowledge

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Mark Zuckerberg makes his keynote speech during Facebook Inc's annual F8 developers conference in San Jose
Mark Zuckerberg makes his keynote speech during Facebook Inc's annual F8 developers conference in San Jose Credit: Stephen Lam/Reuters

Facebook has been paying hundreds of people to listen to users' private audio clips without their knowledge.

The social media giant confirmed that, until very recently, it had employed human contractors to transcribe voice messages sent via its Messenger app in order to check the work of its AI systems.

It is the latest major tech firm to be caught listening to users' messages without their explicit knowledge, following similar revelations about Amazon, Google and Apple.

A spokesman said the company had "paused" the practice "more than a week ago" after other companies' audio listening attracted scrutiny from the press.

Facebook's privacy policy does not explicitly mention that humans will listen to users' audio messages, only saying that it may share "content, communications and other information you provide" with "vendors and service providers who support our business".

It is not clear whether Facebook contractors listened to audio sent by users in Britain or in the EU.

A spokesman said human review had been common practice in the industry until recently, and that the audio clips had been masked to avoid revealing anyone's identity. 

The audio recordings were generated by Messenger's voice chat transcription option, which lets users send voice messages which are then transcribed by AI for the benefit of their recipient.

According to Bloomberg, which broke the news of the practice, workers at an outsourcing company called TaskUs listened to clips, sometimes with vulgar content, in order to check whether the AI had transcribed them correctly. 

Although the clips were anonymised, the workers were not told why they were transcribing them, and reportedly felt that their work might be unethical in light of Facebook's repeated denials that it is listening to users' conversations through their phones' microphones.

Those denials referred to a separate theory held by many users, who believe that Facebook is constantly recording their real-world conversations in order to target adverts at them. Mark Zuckerberg, Facebook's chief executive, has referred to that idea as a "conspiracy theory". 

In follow-up answers for Congress, the company said it “only accesses users’ microphone if the user has given our app permission and if they are actively using a specific feature that requires audio (like voice messaging features.)” The Menlo Park, California-based company doesn’t address what happens to the audio afterward.

The Irish Data Protection Commission said it is now “seeking detailed information from Facebook on the processing in question" and  how Facebook believes that this processing compliant with their GDPR obligations.

The information watchdog will determine whether the social media company, which has its European headquarters in Ireland, has broken European Union data protection laws.

The Irish regulator already has eight active statutory inquiries into privacy incidents from Facebook, the latest from earlier this year, when the company detected a glitch that exposed millions of user passwords to 20,000 employees for years.

The role of humans in studying recordings highlights the limits of artificial intelligence in its ability to recognise words and speech patterns. 

Facebook first started allowing Messenger users to have their audio transcribed in 2015. “We’re always working on ways to make Messenger more useful,” David Marcus, the executive in charge of the service at the time, said in a Facebook post.