Laura Poitras is a documentary filmmaker who did such a good job of making it clear of what the human impact of the Iraq war has actually been, and such a good job of humanizing this atrocity, that she was seemingly retaliated against as a result, which took the form of her being repeatedly searched and detained at airports dozens of times (she has said on NPR about 40 times, IIRC).

Now, as you've alluded to, thanks to recently FOIA'd documents, we now know that the official reason (excuse?) for going after her is that she was filming near Iraqis who attacked US soldiers, and someone decided that she maybe somehow knew about that attack and chose not to warn her fellow Americans.  To date, no evidence that she knew any such thing has been presented.

Once Glenn Greenwald put a spotlight on her harassing detainments, they stopped.

If they genuinely considered her to be a serious threat, I really don't think that Greenwald blogging about the government's detaining of Laura Poitras would have caused them to stop, don't you think?

--Steve