This article contains some thoughts based on the article “Publishing and Linking on the Web” co-authored with Jeni Tennison and Dan Appelquist for the W3C TAG.
If you type a Web address into your browser you will most likely be taken to a Web page consisting of text and images. Sometimes you may be taken to a game where you can pretend to be a race car driver or throw stones at pigs but in most cases, you will get a Web page. From the information on the page you may be able to access related material by simply clicking. This capability is what makes the Web the Web.
If you are creating a Web page you can use material from other sources in different ways. You can provide a link to the material or you can embed it – include or transclude - within your material. These two ways of using material that is not authored by you are quite different and treated differently by courts.
The above page is from http://en.wikipedia.org/wiki/Blue_whale and if you click on the image in Wikipedia it tells you where the image came from and that it is in the public domain “because it contains materials that originally came from the U.S. National Oceanic and Atmospheric Administration, taken or made as part of an employee’s official duties.”
With embedding you see the embedded content on the page. Linking, on the other hand requires a user action. The link requires the user to click on it to be taken to another Web page. There are advantages to inclusion vs. linking. If you include material, that material is not going to change out from under you, whereas material at the end of a link may change. In the worst case, it could be replaced by malware.
In recent years there has been a rash of legal cases relating to linking and embedding. There was, for example, the case of a student who resides in the UK and was facing possible extradition to the United States for posting links on a Web site, which itself is not US-based and is not primarily intended for US users, to material that the US considers to be copyrighted. This case above also raises the question of jurisdiction (more on that later).
The general principle at play here is the notion of agency. If you link to something, you’re less responsible for it being available than if you include it; and if you transclude something, you’re less responsible then if you include it (transclude a copy you made). Most of the questions are whether you’re responsible for making information available that people don’t want to have shared (bomb making, pornography, copyright infringement). If you do decide to embed, the material should be attributed and, unless it is a brief quote, requires permission; otherwise, you may be held responsible for copyright violation.
Linking, is generally allowed — the argument has been made in several places that restricting linking is like interfering with free speech. The idea being that a hyperlink is nothing more than a reference or footnote, and that the ability to refer to a document is a fundamental right of free speech. There have been a few cases in the U.S. that have implied that the act of linking without permission is legally actionable, but these have been overturned.
Still, you need to be careful. The words accompanying a link can express an opinion — for example the HTML code
<pre>Joe’s Bar has < ;a href=”http://joes.bar/menu.html” > great food</a></pre>
links “great food” to the bar’s menu — but some opinions may be construed as defamatory or libellous.
And then again, the material you link to may be so inflammatory that even minor responsibility might be risky; it’s best not to link to Nazi propaganda, child pornography or “How to Make a Bomb”. Web media has been very effective in political campaigns, but if you link to political material it may be judged to be seditious by some governments, and you may be held responsible.
Even though linking, in general, does not violate copyright, some sites may want to restrict linking to all or part of their content.
This Digital Reader article ridicules an Irish newspaper for trying to charge for merely giving directions on where to find information but the request for payment is understandable. If you are a newspaper that invests in creating original content you would like to monetize your investment. The New York Times now allows a certain number of links per month. The Wall Street Journal requires you to subscribe. Other news media have similar policies. So, a link may tell you where to find a book but the library may charge a fee or be accessible only via membership.
Incidentally, links to The Digital Reader where the policy by the Irish newspaper was reported have ceased to work. Thus, while a link may not violate copyright, publishers have the right to restrict linking and may impose a number of conditions such as pay barriers or age verification that must be satisfied before a link is followed.
Restricting Deep Linking
Many web sites restrict deep-linking, i.e. links to pages other than the top page, because this allows links to bypass advertising or the legal Terms and Conditions or because a deep link may leave the source of the material unclear. Often, legal Terms and Conditions are used to restrict deep linking but not only are such terms difficult to enforce, there are simple technical mechanisms that are more effective.
The World Wide Web is truly an international phenomenon and as we have discussed, linking has been compared to freedom of speech. But there are limits to freedom of speech and, as we discuss above, some uses of external material may lead to legal action. If I live in the U.S. and host a web site in a Scandinavian country that has links to offensive material, where could I be prosecuted? If I host a website in a country that does not have a bilateral copyright agreement with the U.S. and the website includes swaths of U.S. copyrighted material, can I be prosecuted? If so, where? In the case of certain kinds of international disputes, there are agreements that such disputes will be settled by mediation or arbitration. Perhaps, we need to formalize a similar capability for the Web.
Linking to material that did not originate with you is an essential feature of the Web and one that gives it much of its power. In general, linking to other material, as opposed to inclusion or transclusion, is safe and carries little risk but, as we explain above, it still pays to be careful.
Standards Professional, Oracle
Principal Scientist Adobe