It's kind of a hobby, but generally known as datahoarding.
Just this morning, I've been trying to find a copy of the "Science Fiction" series (https://www.imdb.com/title/tt1380838/) that has Cliff Stoll's "Cuckoo Egg" tale for the first episode. Unfortunately, can't find it and it may well disappear as "Yorkshire Television" no longer exists as a separate entity. (It's not banned - just obscure enough to vanish)