So, the production of a fansub is illegal, then?
Actually, no! (Surprise!) If you purchase a legitimate source of the original Japanese show (on LD, VHS, or DVD), and then translate it yourself or get a friend to, and run it through the genlock on your computer to add subtitles… then you have a legal fansub. Congratulations. Naturally, this is a heck of a lot of work, and most people can’t get access to genlocks or translations. This is why many fan-subtitlers distribute their work to others. The act of copying the fansub and giving it (or selling it) to other people is the illegal part, and those copies remain illegal. In other words, if you have an anime fansub, and you didn’t make it, it is illegal.