Contractors working for Microsoft are listening to personal conversations of Skype users conducted through the app's translation service, according to a cache of internal documents, screenshots, and audio recordings obtained by Motherboard. Although Skype's website says that the company may analyze audio of phone calls that a user wants to translate in order to improve the chat platform's services, it does not say some of this analysis will be done by humans.

The Skype audio obtained by Motherboard includes conversations from people talking intimately to loved ones, some chatting about personal issues such as their weight loss, and others seemingly discussing relationship problems. Other files obtained by Motherboard show that Microsoft contractors are also listening to voice commands that users speak to Cortana, the company's voice assistant.

Apple and Google recently suspended their use of human transcribers for their respective Siri and Google Assistant services after a backlash over similar media reporting on the companies' practices.

"The fact that I can even share some of this with you shows how lax things are in terms of protecting user data," a Microsoft contractor who provided the cache of files to Motherboard said. Motherboard granted the source anonymity to speak more candidly about internal Microsoft practices, and because the person is under a non-disclosure agreement with the company.

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The snippets of audio obtained by Motherboard are typically short, lasting between five and ten seconds. The source said other passages can be longer, however.

In 2015 Skype launched its Translator service, which lets users get near real-time audio translations during phone and video calls. Before the feature's launch, WIRED published an article titled "How Skype Used AI to Build its Amazing New Language Translator."

The product does use artificial intelligence and the translations are impressive in Motherboard's own tests. But like many other AI or machine learning projects, it turns out that some of the work is facilitated by humans laboring away, completing the very same tasks the AI is supposed to in order to improve the algorithms themselves.

Some of the audio obtained by Motherboard is specified as coming from the Translator feature of Skype's Android app, according to accompanying screenshots of the contractor's screen. An FAQ for Skype Translator says that when people use the service, "Skype collects and uses your conversation to help improve Microsoft products and services. To help the translation and speech recognition technology learn and grow, sentences and automatic transcripts are analyzed and any corrections are entered into our system, to build more performant services." Another section adds, "To help the technology learn and grow, we verify the automatic translations and feed any corrections back into the system, to build more performant services."

That section does not say that humans may listen to audio captured by the Translator feature of Skype's various apps. Microsoft's Privacy Policy does not make this clear either.

"Some stuff I've heard could clearly be described as phone sex."

"People use Skype to call their lovers, interview for jobs, or connect with their families abroad. Companies should be 100% transparent about the ways people's conversations are recorded and how these recordings are being used," Frederike Kaltheuner, data exploitation program lead at activist group Privacy International, said in an online chat.

"And if a sample of your voice is going to human review (for whatever reason) the system should ask them whether you are ok with that, or at least give you the option to opt out," she added.

Pat Walshe, an activist from Privacy Matters, said in an online chat "The marketing blurb for [Skype Translator] refers to the use of AI not humans listening in. This whole area needs a regulatory review."

After reviewing the Skype Translator FAQ, he added, "I’ve looked at it and don’t believe it amounts to transparent and fair processing."

"Companies should be 100% transparent about the ways people's conversations are recorded and how these recordings are being used."

A Microsoft spokesperson told Motherboard in an emailed statement, "Microsoft collects voice data to provide and improve voice-enabled services like search, voice commands, dictation or translation services. We strive to be transparent about our collection and use of voice data to ensure customers can make informed choices about when and how their voice data is used. Microsoft gets customers’ permission before collecting and using their voice data."

"We also put in place several procedures designed to prioritize users’ privacy before sharing this data with our vendors, including de-identifying data, requiring non-disclosure agreements with vendors and their employees, and requiring that vendors meet the high privacy standards set out in European law. We continue to review the way we handle voice data to ensure we make options as clear as possible to customers and provide strong privacy protections," the statement added.

Microsoft said both its Skype Translator FAQ and documentation on Cortana are clear in that the company uses voice data to improve their services. Again, they do not say a human may listen to that voice data, however.

When a contractor is presented by Microsoft with a piece of audio to transcribe, they are also given a series of approximate translations generated by Skype's translation system, according to the screenshots and other documents. The contractor then needs to select the most accurate translation or provide their own, and the audio is treated as confidential Microsoft information, the screenshots show.

"Some stuff I've heard could clearly be described as phone sex. I've heard people entering full addresses in Cortana commands, or asking Cortana to provide search returns on pornography queries. While I don't know exactly what one could do with this information, it seems odd to me that it isn't being handled in a more controlled environment," the contractor said.

Microsoft said audio data is only available to contractors through a secure online portal, and that the company takes steps to remove identifying information such as user or device identification numbers.

Despite the sensitivity of the information, it is at least in part work-at-home contractors who are listening to and handling the Skype and Cortana audio. Motherboard found online job listings from Microsoft contractors that say employees can work from home.

The contractor said, "I generally feel like that while we do not have access to user identifiable information, that if Microsoft users were aware that random people sitting at home in their pajamas who could be joking online with friends about the stuff they just heard that they wouldn't like that."