Chris Baraniuk for the BBC:
Jon Johansen’s program worked. The Norwegian teenager watched as it downloaded 200 megabytes of a recently released movie, The Matrix, from a DVD onto his computer. The program that he and two anonymous others had created that year, 1999, was called DeCSS. But their project was about to cause something of a ruckus. DeCSS allowed people to unlock content on commercial DVDs without the publisher’s permission, so it instantly became the subject of legal objections from the movie industry.
What happened next likely took the lawyers at a number of big movie studios by surprise. Johansen was later acquitted, but wrangling over DeCSS turned into a debate about the essence of computing and what things could logically be banned. The contention right at the heart of this was the fact that any computer file or program could be represented by a number. Could you really make numbers illegal? And if so, what did that mean for the control of information?
In the midst of the debate over whether encryption should — or even could — be made illegal, as it’s simply a series of mathematical equations, this article notes some instances of numbers that are illegal.