Skype worked to enable Prism collection of video calls, [... top-secret] documents [from the NSA's Special Source Operations (SSO) division] show[s ...]. Microsoft has collaborated closely with US intelligence services to allow users' communications to be intercepted, including helping the National Security Agency to circumvent the company's own encryption:

Nine months after Microsoft bought Skype, the NSA boasted that a new capability had tripled the amount of Skype video calls being collected through Prism [...]. “The audio portions of these sessions have been processed correctly all along, but without the accompanying video. Now, analysts will have the complete 'picture'”. [...] ACLU technology expert Chris Soghoian said the revelations would surprise many Skype users: “In the past, Skype made affirmative promises to users about their inability to perform wiretaps”.

“Feedback indicated that a collected Skype call was very clear and the metadata looked complete,” the document stated, praising the co-operation between NSA teams and the FBI. “Collaborative teamwork was the key to the successful addition of another provider to the Prism system.” [...] The NSA was able to start tasking Skype communications [on 5 February 2011], and collection began [the following day]..

☞ In a statement, Microsoft said: “When we upgrade or update products we aren't absolved from the need to comply with existing or future lawful demands.”

☞ These communications [can] be collected without an individual warrant if the NSA operative has a 51% belief that: 1) the target is not a US citizen and 2) [it] is not on US soil at the time.

(The NSA's Special Source Operations (SSO) division [is] described by Snowden as the "crown jewel" of the agency. It is responsible for all programs aimed at US communications systems through corporate partnerships such as Prism. [...] Material collected through Prism is routinely shared with the FBI and CIA, with one NSA document describing the program as a "team sport".)