People who have voice-chatted on Facebook Inc.’s Messenger app might have had their conversation listened to and transcribed, according to a report published by Bloomberg today.

The company has admitted that it did indeed hire third-party contractors to listen to clips but said that the practice stopped “more than a week ago.” The reason they were hired to do it was to check if Messenger chats were correctly being transcribed.

If you didn’t know, there’s a feature in the app that can transcribe audio clips to text, although that feature is turned off by default. The problem is, if one person has consented to have the chat transcribed, the other doesn’t have to give consent. Facebook did say the only people to have their chats transcribed were those who turned on the feature.

Another issue is that Facebook doesn’t explicitly say in its terms of service that humans might be listening into the conversation. “The more you use this feature, the more Voice to Text can help you,” says the support page, only mentioning that the technology uses machine learning.It seems it uses human learning, too, however. The company does add, though, that third-party contractors are used to analyze how the product is used. It just doesn’t say how.

This is a similar issue to last week’s bombshell story that Microsoft Corp. used third-party contractors to listen in to Skype conversations and Cortana commands in order to improve the service. Nowhere did it explicitly state that humans could be on the end of what one contractor said were sometimes intimate conversations.

“Much like Apple and Google, we paused human review of audio,” Facebook told Bloomberg. Indeed, Amazon.com Inc. and Google LLC and Apple Inc. have all used humans to review private conversations. Google and Apple said they have stopped the practice, while Amazon gives users the option not to allow it.

In most case users do give consent to have their conversations analyzed, but the issue is that many of them just don’t realize a human could be listening in, nor are they told they have been listened after the fact. Perhaps in the interests of privacy users might see somewhere in the terms of service the words, “A human might be listening in,” or “Your conversation was analyzed by a human.”

Photo: Kārlis Dambrāns/Flickr