There are red faces in Redmond after Edward Snowden released a new batch of documents from the NSA's Special Source Operations (SSO) division covering Microsoft's involvement in allowing backdoor access to its software to the NSA and others.

Documents seen by The Guardian detail how the NSA became concerned when Microsoft started testing Outlook.com, and asked for access. In five months Microsoft and the FBI created a workaround that gives the NSA access to encrypted chats on Outlook.com. The system went live in December last year – two months before Outlook.com's commercial launch.

Those Outlook users not enabling encryption get their data slurped as a matter of course, the documents show. "For Prism collection against Hotmail, Live, and Outlook.com emails will be unaffected because Prism collects this data prior to encryption," an NSA newsletter states.

Microsoft's cloud storage service SkyDrive is also easy to access, thanks to Redmond's work with the NSA. The agency reported on April 8, 2013 that Microsoft has built PRISM access into Skydrive in such a way as to remove the need for NSA analysts to get special authorization for searches in Microsoft's cloud.

"Analysts will no longer have to make a special request to SSO for this – a process step that many analysts may not have known about," the leaked NSA document states. "This new capability will result in a much more complete and timely collection response. This success is the result of the FBI working for many months with Microsoft to get this tasking and collection solution established."

The documents also detail how Microsoft and Skype have also been working with the intelligence agencies to install monitoring taps. Work began on integrating Prism into Skype in November 2010, they state, three months before the company was issued with an official order to comply by the US Attorney General.

Data collection began on February 6, 2011, and the NSA document says the planned systems worked well, with full metadata collection enabled. It praised Microsoft for its help, saying "collaborative teamwork was the key to the successful addition of another provider to the Prism system."

Work to integrate Skype into Prism into Skype didn't stop there, however. In July 2012 an NSA newsletter states Microsoft installed an upgrade that tripled the amount of Skype videos that can be monitored by NSA analysts.

"The audio portions of these sessions have been processed correctly all along, but without the accompanying video. Now, analysts will have the complete 'picture'," it says.

In a statement, Microsoft said that it only complies with legal demands for customer information for law enforcement and national security purposes, and that the company isn't involved in giving "the kind of blanket orders discussed in the press over the past few weeks."

"When we upgrade or update products legal obligations may in some circumstances require that we maintain the ability to provide information in response to a law enforcement or national security request. There are aspects of this debate that we wish we were able to discuss more freely," it said.

Not that Microsoft hasn't been making a big thing about the privacy of its communications systems in the past. Its Gmail Man ad campaign lambasted Google for snooping in people's mail to match them with advertisers, and the tagline "Your email is your business" seems somewhat ironic these days. The advert is no longer on Microsoft's YouTube channel.

The leaked documents come from the NSA's Special Source Operations (SSO) division, which handles commercial company liaison for data collection by the agency. The documents show that, once collected by Prism, the NSA shares its data directly with the CIA and FBI via a custom application.

"The FBI and CIA then can request a copy of Prism collection of any selector..." the document says. "These two activities underscore the point that Prism is a team sport!"

In a joint statement, Shawn Turner, spokesman for the director of National Intelligence, and Judith Emmel, spokeswoman for the NSA, told The Guardian that the wiretapping referred to in the document was court-ordered and was subject to judicial oversight.

"Not all countries have equivalent oversight requirements to protect civil liberties and privacy," they said. "In practice, US companies put energy, focus and commitment into consistently protecting the privacy of their customers around the world, while meeting their obligations under the laws of the US and other countries in which they operate." ®