Take Luke Harding @guardian.
"They" aren't Luke's "source." He is their asset. He was an easy mark B/C of his work & he got played.
That's just one Eg. But they know he desperately wants it to be true. So, they're going to tell him what he is dying to hear.
Damn sure someone going into an embassy is going to be on candid camera. Did he check?
Think again.
The job is to mark, entrap marks & convert them into assets to exploit! exploit! exploit! When used up, they're burned like Page.