Can You Own a Number? The Bizarre Legal War That Almost Made Math Illegal

Here is a number: 13,401,676,639,3.

You just read it. You might write it down. You might tell it to a friend. And in the late 1990s, doing exactly that — sharing a specific sequence of digits — could theoretically have gotten you sued, or worse, prosecuted under federal law.

This is not a hypothetical. It actually happened. And the story of how a string of numbers became a legal weapon is one of the strangest intersections of mathematics, intellectual property, and constitutional law in recent American history.

The Number That Started a War

In 1999, a group of programmers cracked the encryption system protecting DVDs — a system called CSS, or Content Scramble System. The crack itself was published online as a small piece of code called DeCSS. The code was compact enough that, once you stripped it to its mathematical core, it could be expressed as a very large integer. A number.

The DVD Copy Control Association, backed by major Hollywood studios, went to court. Under the Digital Millennium Copyright Act, passed in 1998, they argued that distributing DeCSS — in any form — was illegal circumvention of a copy-protection system. Courts agreed. Websites hosting the code were ordered to take it down.

What happened next was remarkable.

Because the underlying code was mathematically equivalent to a number, and because that number could theoretically be expressed in an almost infinite variety of formats, the internet responded with one of the most creative acts of protest in the history of digital culture. Programmers encoded the number into images, into music files, into haiku, into prime number lists. Someone embedded it into a JPEG of a coffee cup. Someone else turned it into a quilt pattern. T-shirts appeared. Bumper stickers appeared.

And at the center of all of it was a single, deeply strange legal question: if a number is protected intellectual property, does the First Amendment protect your right to write it down anyway?

When Math Meets the Law

The DeCSS case — formally Reimerdes v. 2600 Enterprises — was decided in favor of the studios. Judge Lewis Kaplan ruled that the DMCA's restrictions on distributing circumvention tools were constitutional even when those tools were expressed as pure mathematical content. The code, he argued, was functional regardless of what form it took. Its purpose was to do something, not just to say something, and that functional nature removed it from full First Amendment protection.

This ruling made legal scholars deeply uncomfortable, and not without reason. The logic, followed to its conclusion, suggested that a number — an abstract mathematical object that exists independently of anyone's creativity or effort — could be regulated by law based on what it was capable of doing. Which raised an obvious question: where does that end?

Numbers, after all, underlie everything. The same mathematical principles that encrypt a DVD also encrypt your bank account, your medical records, and your text messages. If the legal system could restrict the distribution of one number because of its functional implications, what was to stop it from restricting others?

The Broader History of Trying to Own Math

The DVD fight was the most dramatic, but it wasn't the only time someone tried to put a fence around a number.

In the world of intellectual property, there's a long and occasionally absurd history of attempts to claim ownership over mathematical concepts. The formula for calculating a specific type of industrial rubber was at the center of Diamond v. Diehr, a 1981 Supreme Court case that helped define the boundaries of software patents. The court ruled that mathematical formulas themselves couldn't be patented — but that processes using those formulas could be. The distinction sounds clean in theory and has been an absolute mess in practice ever since.

In the 1990s, the Compton's NewMedia company briefly held a patent so broad that it appeared to cover the general concept of multimedia search — a claim that, if upheld, would have required royalty payments from virtually every technology company in existence. The patent office eventually invalidated it, but not before the industry spent years in low-grade panic.

More recently, debates over the patentability of gene sequences — which are, at their core, long strings of biological information expressible as numerical code — have raised similar questions in a medical context. The Supreme Court addressed this in Association for Molecular Pathology v. Myriad Genetics in 2013, ruling that naturally occurring DNA sequences couldn't be patented. But the line between "naturally occurring" and "synthetically modified" remains contested.

The Number That Cannot Be Named

Back in the DVD wars, the protest movement surrounding the DeCSS number produced something genuinely fascinating: a community of mathematicians and programmers who started treating the number itself as a kind of free speech symbol. Wearing the number on a t-shirt became a statement. Posting it became an act of civil disobedience.

Some participants pointed out, with a certain dry humor, that the number in question was what mathematicians call a "prime" — divisible only by itself and one. It was, in other words, a fundamental mathematical object. Claiming legal ownership over a prime number was, they argued, roughly equivalent to claiming ownership over the color blue or the concept of multiplication.

The courts didn't fully accept that argument, but they didn't fully reject it either. The legal status of mathematical expression remains genuinely unsettled. Patent law, copyright law, and trade secret law each approach the question differently and reach different conclusions. And the rise of AI, cryptography, and algorithmic systems has made the stakes considerably higher.

So Can You Actually Own a Number?

The honest answer is: it depends on the number, what it does, and who's asking.

A pure abstract integer — the number 7, for example, or pi — cannot be owned. Courts have been clear on that. But a specific sequence of digits that functions as an encryption key, or a formula that underlies a patented industrial process, or a gene sequence that's been synthetically engineered? The legal ground gets murkier fast.

What the DeCSS case demonstrated, more than anything, is that the question isn't really about numbers at all. It's about function. It's about what a sequence of digits can do once it leaves your hands and enters someone else's computer. And in a world where information is increasingly indistinguishable from action, that question is going to keep getting more complicated.

In the meantime, the number that started the whole fight is still out there. It's been printed, shared, tattooed, and sung. It's on servers and in archives and probably on a coffee mug somewhere in a programmer's kitchen.

The law said you couldn't share it. The internet disagreed.

The internet, as usual, won.