It's not yet clear that anything in the original piece is actually wrong, despite some carefully worded denials. I think it's unfair to judge him as misinterpreting something (yet).
As best as I can tell Greenwald was claiming that the NSA managed to backdoor most major Internet PIM service providers for the unbelievably low cost of $20 million.
You couldn't really do that for $20 million just on labor cost alone, so it was clear there was more to the story, it was just a question of what.
To be clear the story is important enough that I don't think it should be required to overstate or mislead either. Transparency of data collection and intelligence services is a conversation that America should at least have, whether it's backdoors or not.
