He left The Guardian.

Here's a quote from a recent interview he gave to the Guardian:

> The move [to create his own journalistic enterprise] was audacious and bold, but when I raise it with him he's in a surprisingly reflective mood. He's had some feelings, if not of regret, then perhaps of a little guilt at having left the Guardian at a time when the NSA disclosures were still blazing. "I don't want to say betrayal, that's too strong, but a lack of loyalty ..."

http://www.theguardian.com/world/2014/may/12/glenn-greenwald...

That's beside the point though. What matters are the disclosures. Not who makes them and not the newspaper where they appear. The disclosures are all that matter.