This is a big pet-peeve of mine because of all of the (mis)information being spread by everyone and their mom. Time after time UC Davis staff told us about all the terrors of using Limewire and Bittorrent, from orientation to welcome week. Telling us about how the music industry is targeting University IP addresses and that X number of students got sued last year.
Then enter me, someone who actually uses Bittorrent for what it is designed for: content distribution.
Content distribution. Not file sharing, content distribution. Bittorrent requires that you goto a website a download a small .torrent file, then load it in your BT client and then it'll download the file. When used for file sharing, these websites where you download the .torrent become the point of failure, which is a feature. Content distribution means that indie content producers can distribute their content at significantly less cost.
If I make a movie, and then post the .torrent for it, there is nothing illegal about it. I created my own content, I own the copyright to it, and I choose to give it away to others using Bittorrent. Granted, I've never created a movie worth distributing on Bittorrent, but others do, and I download them.
Bittorrent is a great technology designed to allow small publishers to push huge amounts of data out to a huge number of people. One of the things I download with Bittorrent most often is Linux disc images. These things are 600MB and I usually download at least four a year. Multiply that by the 1000s of people who download each disc image along with me, and you have a mind blowing amount of bandwidth straight to the server. Instead, each person who downloads the image only needs to donate 600 - 600 / (n-1) MB of bandwidth back to the producer, which I usually find a fair trade since I'm only downloading it in the first place because I think it's good content, and giving them my internet connection is the least I can do.