Facebook has hired hundreds of contractors from outside the company to listen to and copy audio conversations from its users, US media reported.
Facebook admitted to copying the talks, which Bloomberg revealed for the first time, but told the US media group in a statement that the hearing had been authorized by users and that the practice had been stopped.
"Just like Apple and Google, we stopped the human voice review more than a week ago," the statement said.
According to Bloomberg, contractors were testing Facebook's AI ability to interpret messages. The affected users are only those who used Facebook Messenger and gave consent to copy their voice chats.
The Bloomberg Group said contractors working on the project had "taken care of them" to listen to private chats, whose identities were not disclosed, which sometimes included obscene content.
It added that contractors were not told why they were copying chats. Apple, Amazon, Google and other companies working on voice aid projects have acknowledged collecting voice talks, saying they are to improve their products.
Google and Apple said they have stopped the practice in recent weeks, while Amazon is still giving users the option of banning the collection of their voices by Alexa, an artificial intelligence program behind Echo's voice assistant.
Facebook, which was recently fined by the FTC for $ 5 billion for misusing its users' data, gave different answers regarding reports of its use of audio recordings for advertising or to make its pages more attractive.
While Facebook CEO Mark Zuckerberg last year denied plotting a Senate testimony, the company later told lawmakers in writing that it was already gathering the talks if the owners allowed it.