I like to get up in the morning and see a nice list of countries downloading a file I'm sharing on BitTorrent. It feels good to share, especially when it doesn't cost you nuttin'. 😀
I only share legal files, like music licensed under Creative Commons, or Linux iso's licensed under the GPL. I don't "keep it legal" out of any sense of morality. If I want something else, I know how to get it, though I've never done such a thing.
The Linux iso I'm sharing is one I got via bittorrent. It was about 700 MB in size, and I've sent back out over 12 GB. My ISP will try to hurt me one day, I suppose. :p
I enjoy using an operating system that was written by people all over the world, and was assembled by bittorrent from all over the world for my download. It's really world-class fun to use, too!