Keith's note: After using Uncle Google for a while and searching for NASA airplane tail numbers etc. I came across a website run by NASA Ames online at http://asp-archive.arc.nasa.gov If you go here you can download all kinds of NASA airplane and drone footage going back a number of years. This really, really ugly HTML 1.0-flavored NASA website is sort of a central uploading point for lots of NASA aircraft imagery and flight data before that data is used by various programs for their research activities. No hacking or FOIA requests required. As best I can tell, some of these "hacked" YouTube videos would seem to have been from NASA's DC-8 N817NA and also NASA 439 C-130H (neither of which are "drones", BTW).
And of course if you go to this other NASA website https://airbornescience.nasa.gov/aircraft_detailed_cal you can see which NASA planes went where over the past few years via a somewhat better designed website. Nothing is being done in secret.
So -- everyone needs to get busy downloading these oh-so-secret NASA videos and then upload them to YouTube with hashtags suggesting that they are somehow #clandestine or #secret or involved with #chemtrails
"Cowing challenged the hackers to release the logs of their activity if they really want to prove their claims. At the same time, he also admitted that it's possible that the group did get into some NASA system and didn't even realize where they were. "They may have hacked in but their gopher tunnel may have gone sideways as opposed to deep in, and they just bumped into something that was already publicly available," Cowing told me. With the new evidence he found online, that theory appears more likely every day."