The story was that they admitted this in a "secret briefing". I'm not sure if denying something in public refutes what you said in private.

Nadler seemed pretty sure on Thursday at the Committee meeting and when interviewed by CNET over the weekend but has now changed his story. The NSA released a very strangely worded denial. And in today's Q&A Snowden says this is exactly how it happens.

Not sure what to make of all this but is seems like we have been given a peek behind the curtain but not a long enough gaze to see exactly what is going on.