ZRTP http://en.wikipedia.org/wiki/ZRTP http://en.wikipedia.org/wiki/ZRTP As others have said, end-to-end encryption this not solve the problem of calculating a

ZRTP http://en.wikipedia.org/wiki/ZRTP http://en.wikipedia.org/wiki/ZRTP As others have said, end-to-end encryption this not solve the problem of calculating a persons social networks and the strength of those connections by correlating calling frequency and duration (as the information in the leaked court order could be used to do). For that you would need a Tor-like network. The Guardian Project have attempted to do some work in this area, sending VOIP over Tor, but the latency is quite high at the moment: so it requires using some of the old radio protocols when there was a possibility of interference and to make it clear when you had stopped talking "over and out", "roger" etc.