Usenet is something of a forum, where members can have discussions. It also has the ability to host files, but broken up into a lot of pieces. It's kinda hard to find anything, but some people have put effort into indexing what's scattered across the Usenet spaces. You can subscribe to their index, and find what you're looking for in the usenets you're a member of. There are programs that will then take all those pieces, download them—since it knows where to look now—and put them back together again, resulting in a working file. And since buying isn't owning… I see no problem with this.