They mentioned having a "web of trust" to help fight spam. But if you use that, doesn't it mean someone like NSA, who can get everyone's public keys (which I as

They mentioned having a "web of trust" to help fight spam. But if you use that, doesn't it mean someone like NSA, who can get everyone's public keys (which I assume is what they're going to use for this, just like for PGP), could then identify who are the people talking to each other, and essentially invalidate all their metadata gather protections? Or would that key be ephemeral, too?