Yahoo scanned all customer emails for US intelligence agencies

Yahoo wrote software last year to scan all of the company’s incoming emails for certain content, anonymous Reuters sources say. The American company would have done this at the request of the NSA or FBI.

While Silicon Valley normally fights such requests tooth and nail, it wouldn’t have happened in this case, say the sources, which consist of three ex-employees and one person involved. It would be the first time that this is so easy. It would also be the first time that surveillance would take place across the board, rather than specific email accounts being monitored. It is unclear what was sought and whether any data was handed over to US security and intelligence services.

Yahoo would not have challenged the contract because it believed it would not win the dispute, the sources say. That sentiment would come from past classified filings that the company would have unsuccessfully challenged. The decision is also why Yahoo security chief Alex Stamos stepped down from his position in June 2015 and took the same job at Facebook, according to the sources, although he didn’t mention it in his announcement.

Requests from intelligence and security services are said to increase due to increasingly strong encryption, which makes interception of emails more difficult. Yahoo has been promising end-to-end encryption to its mail service since 2014, which should make this kind of practice completely impossible, even for Yahoo itself. However, end-to-end encryption is still not available from the email provider. It is still being worked on.

Yahoo, Stamos, and the NSA refuse to comment substantive to the American news medium. Google and Microsoft tell Reuters that they have never engaged in such practices, but are not commenting on whether they have been approached with the same request.

Yahoo also recently confirmed that state hackers from an undisclosed country had stolen the data of approximately 500 million accounts.