"This is a major leap forward in the NSA's ability to exploit Facebook using FISA and FAA authorities" - NSA

"...by exploiting inherent weaknesses in Facebook's security model." - GCHQ

http://hbpub.vo.llnwd.net/o16/video/olmk/holt/greenwald/NoPl...

That's Facebook. The Yahoo and Google stuff has been very widely reported and are direct from Greenwald and the Snowden leaks. Other links (in particular the PKH link) contain other information.

http://www.washingtonpost.com/world/national-security/nsa-in...