What technology allows such rigid restrictions? Encryption plus digital signatures (see Digital Certification). Together, they give a DVD manufacturer complete control over how you watch the DVD, including which players you can watch it on. It's like buying a book that you can't open except in England, and only between 1:00 and 5:00 in the afternoon.

The encryption and digital signature system for DVDs is called the Content Scrambling System (CSS).

But a group of hackers wanted to watch videos on their computers. After all, what would be the harm in watching videos purchased legally on the device of their choice? They analyzed the cryptographic code and created DeCSS, a program that can correctly decipher videos coded with CSS.

The increasingly popular Linux operating system provided a particularly strong reason to developed DeCSS. Microsoft and Apple paid licensing fees to DVD companies so they could get the encryption keys that unlock DVDs, but Linux computers didn't have these keys because Linux is a free operating system distributed openly on the Internet. Companies can bundle Linux with other software (for a price or at no cost), so these companies sometimes pay the licensing fees and include keys. But few Linux users get their systems that way.

CSS happened to be poorly designed, making it easier to break (one film studio even included their key openly on their DVDs. They were supposed to encrypt the key, but forgot). Nevertheless, every similar copy-protection scheme has been broken by hackers. The idea behind content protection is fundamentally unviable.

One young Norwegian called Jon Lech Johansen shared DeCSS with other Internet users. The film industry and its associates, especially the MPAA (Motion Picture Association of America), sued Johansen and had his home searched by police in 1999. Jon was being sued for “piracy.”

Despite pressure from powerful interests in Hollywood, Jon was acquitted of the charge in January 2003. By this time, he was already known worldwide as Jon DVD. In her ruling, Judge Wenche Skjeggestad said that no one, much less the young Jon, could be sentenced for copying or watching films purchased legally on any device of his choosing.

Instead Jon should be awarded a medal for breaking a “linked purchase” or “linked products” scheme, which is illegal in most countries. The principle Jon upheld was the right to buy one item without having to buy something else—that is, to buy a film without buying one of a small set of expensive DVD players.

In many countries, these linked product schemes are common. For example in São Paulo, Brazil, if you want a broadband connection through the telephone company, they require that you also use Windows software in your computer. The company's customer service used to tell customers that the connection wouldn't work with Linux, which is actually untrue (the same attempt at limiting service is common in the United States too).

The Windows requirement is an outrageous linked product scheme, conducted between the telephone operator and the (former) monopoly software manufacturer. After receiving many complaints, customer service now says that the connection will work with Linux, but they won't provide technical support if you don't use Windows. This is an illegal operation that strengthens monopolization, not competition.

DVDs are still not totally free. In the United States, a law makes this software illegal. This is another terrible result—perhaps the worst result—of the film companies' attempt to control the watching of their movies. Now the government has the right to step and outlaw the creation of certain types of software. If a company can persuade a court that some software breaks an encryption program that they put on their product, the court can jail the people who created the software. They can even jail you for distributing software created by someone else! (this law is a large collection of provisions called the Digital Millennium Copyright Act or DMCA, and the part discussed here is called the “anti-circumvention provisions,” because using DeCSS circumvents the software installed by the DVD manufacturer).

Many other countries have passed similar anti-circumvention laws, under pressure from the United States government and various firms in industries like film and music.

The DMCA is not the first instance of outlawing software. Similar restrictions were passed many decades ago, the focus also being encryption. The US wanted to keep people from sending encryption software outside the country, hoping to keep enemies of the US from using it.

This attempt was ridiculous, because the US couldn't monitor every electronic transmission to see whether it contained particular software. In addition, the knowledge about how to write encryption software was openly published in many books and journals, so any programmer in the world could write his own program. The regulations simply held back commerce, left ordinary users open to malicious attacks on data, and made it difficult to exchange software because many packages needed to be divided into two parts (one of which could be distributed internationally and one that could not).

The restrictions were overturned by a series of court cases by privacy advocates during the 1990s. But new restrictions are now in place thanks to the DMCA.

Still, DeCSS and other programs are widely available. Thanks to Jon DVD we can now watch a video on any computer in any part of the world. This is how Jon DVD freed videos from the prison in which they were cast. And DeCSS hasn't hurt the profits of the film studios in any noticeable way.