There were fanworks for B5 -- pre-internet. A lot of vids and fic were offline only; I know of at least one Media Cannibals vid (Susan/Talia). I used to be a member of a fanclub of B5 in the city I lived which were very prolific filk writers and shared a few stories around. There were a few zines, too. I don't know what happened to all the content, all the vids and things, if people have copies still. Hopefully they'll make their way online someday!