It's reassuring to see that Ms. Poitras did not feel the need to be so careful with Russia's FSB. Why, they even helped her keep her "scoop" secret until her news of her movie revealed that Lindsay Mills had been brought into Moscow to join Edward Snowden, which was very nice of them.
After all, it's not like they had to edit Mills out of this story: http://lifenews.ru/news/137867 posted a couple of months ago on Aug. 5th (LifeNews is closely affiliated with the Kremlin: http://bigstory.ap.org/article/russia-media-tycoons-expand-k...)
To whom? Nobody besides the government could serve the role you suggest. Should reporters register with the government to ensure they are only investigating and reporting on things they are permitted to report on?
While that kind of thing might fly in North Korea, China, Russia, or Iran, in the US there's a Constitutional amendment barring that kind of thing, so it wouldn't work here.
"Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances."
Are we nearing a time where journalists simply won't be able to?