At the same time, if you're smart you'll notice the propaganda pieces circulated by AP on-behalf of USA.
One of them is Twitter. "identified accounts" but they aren't shut down or shunted. Why's that?
Simple - once you identify a target and they're vocalizing their thoughts, why do you want to limit and censor them? allow them to post, collect metadata and help it tie together other pieces of the puzzle.Browser ident, time, date, time of access, ip address, etc.
Meanwhile you'll see in the article a different reason as to inaction.
Although I don't know, I think this story was released for exactly that purpose, to improve public support for the NSA and Cyber Command. With Snowden being in the news lately I'm sure they're looking for opportunities to run cool war stories to balance out their image.