Search for any website that has had to limit the downloads of files in some manner, be it by making available small set of their content at once, a username/password scheme or limited number of files/IP/day. They're not hard to find, spend five minutes googling to see for yourself.

These are all people with content they want to give away, but for whom the 'publisher pays' configuration of the Web isn't working. No better solution exists today than for them to put their file on the gnet and magnet links of the web site.