DeCSS is not illegal
This is a stone in the Pigopolists garden, a norvegian court has ruled that its legal to use DeCSS code to watch legally obtained DVD films, at least in Norway.
Since common sense has no longer droit de cité in the Pigopolists' world, something as basic and simple as fair use -- which is perfectly legal today -- is going to be illegal tomorrow, unless something (like a court) or someone (like you) prevent that to happen.
Today you can buy a CD (usually for a rather expensive price) and enjoy it on your hifi set, on your computer, on your MP3 player or whatever device of your wish. You pay the artist (a little) and intermediaries (a lot) for the right to listen to an oeuvre in fair use. Same for other oeuvres in other forms, e.g. it is perfectly legal to share a book that you own with other people. At least today.
Tomorrow, if Pigopolists win, all of this will be illegal, or impossible. Some CDs sold today already sport weird hacks that prevent them to work with computers CD players. The law in the USA (DMCA) and in Europe (European Commission's Copyright Directive) is making this trouble-free for the industry, i.e. you -- the consumer -- will not be able to complain or even get a refund because the CD you bought does not play where the editor does not want you to listen to it, and you'll get into jail if you try to get around to recover your past fair use rights. And if you think I'm a bit paranoid about books, it's time to watch what's going on with ebooks.