Its not infeasible that governments has done such things. It may even be highly probable.
But when i see "The CIA admits [...]" linking to nytimes, claiming to have a CIA document, which for all I know could be fake. What truth assertment can I make from that? Its claims against claims.
I think it would take some serious work to determine the validity of all of these claims. That's something that I haven't got the time for. It also seams, to me, that no scientific approach is taken towards this.
However much suggests that privacy is "the good" and governments are "evil", I cant express that as clearly as I can express mathematical proofs. And thisfar I think the evidence is too scatterd and unorganized to say anything with high degree of certainty.