Any extra steps to post content can mean the difference between something going viral and something remaining unseen in the dark corners of the Internet. I don't know if this is a good comparison, but this reminds me of the piracy study[1] that said piracy was beneficial for sales. These lists are a way of "pirating"/distributing content, though it seems without any real gain to the original creator due to lack of attribution (that's where the comparison definitely breaks down). I suppose the two would be more similar if you could somehow watermark the content to somehow point it back at the creator
Obviously, this method is really annoying for a lot of us, but the fact that it works so well and is generating all that traffic, likens it to all that Viagra spam we get -- people keep clicking! I don't know if there's any amount of technology that will help people gain common sense
[1] http://torrentfreak.com/bittorrent-piracy-boosts-music-sales...