Stock: 9/11 Chronology - Source Material
The CNN and Fox live news footage found in 9/11 Chronology I purchased in 2004 via eBay. After I completed the project, I deleted the digitized copies from my hard drives (they were too big to archive easily). Since I've been asked many times for copies of this footage, I re-digitized it and created a simpler split screen which I've posted to Internet Archive. (I can't post anything simpler then a split screen because the footage is copyrighted, and I need some sort of recontextualization of the footage or else IA will not host it.)
There are lots of source files which I've already described on a dedicated IA splash page here.
And please understand this "stock" footage is still copyrighted by CNN, FOX, etc. Documentaries are given greater flexibility under copyright law than works of fiction. You can presume (like I did with 9/11 Chronology) that you have recontextualized the footage enough to be safe, but FOX may not see it that way.