copyright
Can numbers be illegal?
<p><a href="https://www.youtube.com/watch?v=LnEyjwdoj7g" rel="nofollow">This video</a> explaining <a href="https://en.wikipedia.org/wiki/Illegal_prime" rel="nofollow">this wikipedia article</a> says that possessing a particular number can be illegal.  Is this true?</p>

<p>From the article (internal links and formatting removed):</p>

<blockquote>
  <p>An illegal prime is a prime number that represents information whose possession or distribution is forbidden in some legal jurisdiction. One of the first illegal primes was found in 2001. When interpreted in a particular way, it describes a computer program that bypasses the digital rights management scheme used on DVDs. Distribution of such a program in the United States is illegal under the Digital Millennium Copyright Act. An illegal prime is a kind of illegal number.</p>
</blockquote>

<p><a href="https://en.wikipedia.org/wiki/Illegal_number">Wikipedia explains this well enough</a>: Particular numbers can be trade secrets, and their reproduction and dissemination may be particularly proscribed, e.g., by the U.S. DCMA.</p>

<p>As a coarse analogy: Your social security number is not "illegal."  But if somebody entrusted with it shared it in violation of law or contract then their communication of the number <em>in a context that allowed potential identity thieves to associate it with you</em> would be illegal.</p>

<p>To answer follow-up questions in the comments: Sure, "mere possession" of a number can land one in jail for all sorts of crimes, just like "mere possession" of stolen property can.  For example, if you possess a bank account number, credit card number, or PIN, and you "conspire, confederate, or combine with another" person who actually commits fraud or theft using that number, then you can be convicted of the same crime.  This is so common that a search for "conspiracy to commit wire fraud" or "credit card fraud" provides ample reading.</p>

<p>A number is just information, and any information that an be encoded digitally has at least one corresponding number. So if there's information that can be encoded digitally that is illegal to possess, then there are numbers that are illegal to possess.</p>

<p>There are very few cases where mere intentional possession of information is illegal with no other elements at all, at least in most major countries. The most obvious example of such numbers would be digitally encoded images of illegal child pornography. Some countries have "born secret" laws that make it illegal to possess certain categories of information such as those relating to the design of nuclear weapons.</p>

<p>While there are few cases where mere intentional possession of a piece of information is a crime, there are all all kinds of "possession plus" offenses, where some additional act or element relating to the possession makes it illegal. In some jurisdictions, knowing possession of information obtained in specific illegal ways is illegal. Similarly, possessing information with intent to use it in a particular way or as part of a conspiracy to commit a crime can be illegal.</p>

<p>The "plus" part of many of these offenses can take place entirely in your head. For example, <a href="http://www.leg.state.fl.us/Statutes/index.cfm?App_mode=Display_Statute&amp;URL=0800-0899/0817/Sections/0817.568.html">Florida Statute 817.568(2)(a)</a> makes it illegal to possess certain identifying numbers if you intend to use them fraudulently. This is a law that explicitly makes it illegal to possess certain numbers if you have the wrong thoughts in your head about them.</p>

<blockquote>
  <h2>Can numbers be illegal?</h2>
  
  <p>This video explaining this wikipedia article says that possessing a particular number can be illegal. Is this true?</p>
</blockquote>

<p>If your question, as given in the topic, is interpreted <em>literally</em>, without the context from that video and article and without any possible other interpretations, then the answer is clearly and absolutely "no". </p>

<p>It is not possible that "possessing" a particular number can be illegal, in any form or fashion.</p>

<p>All cases mentioned in the other answers, as well as in your text and video, are not the possession of a "number", but of some information "xyz" which happens to contain a number as part of it.</p>

<p>Let me give you a simple example: say I write a diploma thesis and count the number of cars that drive by my home during a day. I end up at 322884 (it's a busy street). It just so happens that the PIN for launching the nuclear arsenal of my country also happens to be 322884. If it were illegal to possess that number, I would go to jail.</p>

<p>Sure, I do "possess" that <em>number</em>. It is clearly written on my hard drive, I have printed it on my thesis, I have even publicised it. So if the NSA does a full-out scan of all my property, they would easily find it. I did <em>not</em> possess the information that it is the nuke-PIN, though. So I will most certainly not go to jail for it.</p>

<p>TL;DR: yes, it can be illegal to possess a certain information. No, it cannot be illegal to possess a certain number (without connotation).</p>

<p>If you represent an image as a number where each pixel is represented by a number of bits you can represent an image as a single number. This is commonly the form images are stored on disk.</p>

<p>As there are images that are illegal to posess (in most countries I suspect) then the number that represents an image depicting child pornography could be considered illegal.</p>
