I can think of exactly one case! In college there was, for a glorious, brief, time, a program called mytunes. It would scan the network for iTunes instances th

I can think of exactly one case! In college there was, for a glorious, brief, time, a program called mytunes. It would scan the network for iTunes instances that had the network sharing turned on. Then it allowed you to copy over entire iTunes libraries (iTunes only let you play songs from other users). I would log on to the dorm network which normally had dozens of iTunes instances running at a go, and just copy everything to my, at the time, massive 160gb drive. Then you would dedupe. That’s the last time I thought about deduping