I ran an open CIFS volume (windows share) in our dorm for music and movies. This was just after Napster went down but before Limewire or something. So the only way to share music was to upload everything you had and have access to whatever everyone else uploaded. You just dropped what you had in a writable folder and it would organize it in read only folders, doing any deduping for identical files and flagging non-identical files with the same meta or anything it didn’t understand.