This is all thanks to ABC archiving everything, not an employee saving a tape. However that does happen sometimes at other networks.
ABC and WGBH/PBS are some of the better ones you can find almost full digitized archives of online. Other broadcasters like NBC didn't save tapes until 1980 (multiple Late Night with Letterman episode masters being lost as an example). CNN is another somewhat bad one, they literally threw all the masters to their theme music in the dumpster, but an employee saved them all. They have an internal archive of tapes as well as the "CNN Collection" but it's spotty.
Yep. ABC is less digitized and hides most full broadcast programs from the public (gotta be an employee for that). But https://www.abcnewsvsource.com/ is the Silverlight run site with everything. Someone should probably archive everything incase the Silverlight shutdown this year kills the site. Ripping it is mildly easy.
PBS/WGBH stores everything at https://americanarchive.org/ which for copyright reasons, some stuff can only be viewed at the LOC or WGBH. The physical only content includes a number of interesting items though like the few Mr. Rogers episodes not aired on Twitch, or around 2000 non-public but aired Sesame Street episodes.
Archive Team already has some private archives of news stuff that I assume they'd like to add to. They have rips of every nightly news broadcast from 1969 till 2018 which they'll probably never release. Would love to help them though.
