- See also Copyrighting
Copyright is a form of intellectual property law that exists fairly uniformly around the world. Copyright is a property grant on creative works granted to authors of those works for a period set by law, after which the work is no longer protected by copyright and becomes public domain. The term length and conditions for copyright vary.
Copyright law invariably includes exemptions for what US law calls fair use, though the terminology and details vary from country to country. It does not violate copyright to quote a work in a review or scholarly study, or to parody it, for example. In some countries, things like photocopying newspaper articles for use in a classroom are covered by this; in others, they are not.
Another complication is work for hire. For example, if a newspaper sends a reporter and a photographer out to cover a story, the copyright on both article and photos is owned by the paper, not by the creators.
British copyright law
Britain enacted the first copyright legislation, the Statute of Anne, in 1710.
WHEN Parliament decided, in 1709, to create a law that would protect books from piracy, the London-based publishers and booksellers who had been pushing for such protection were overjoyed. When Queen Anne gave her assent on April 10th the following year—300 years ago this week—to “An act for the encouragement of learning” they were less enthused. Parliament had given them rights, but it had set a time limit on them: 21 years for books already in print and 14 years for new ones, with an additional 14 years if the author was still alive when the first term ran out. After that, the material would enter the public domain so that anyone could reproduce it. The lawmakers intended thus to balance the incentive to create with the interest that society has in free access to knowledge and art. The Statute of Anne thus helped nurture and channel the spate of inventiveness that Enlightenment society and its successors have since enjoyed.
In the 1840s, the law was revised, extending the term of copyright. Thomas Macaulay spoke in parliament against the idea of extending it too far.
The advantages arising from a system of copyright are obvious. It is desirable that we should have a supply of good books; we cannot have such a supply unless men of letters are liberally remunerated; and the least objectionable way of remunerating them is by means of copyright....
I propose to add fourteen years to the twenty-eight years which the law now allows to an author. His copyright will, in this way, last till his death, or till the expiration of forty-two years, whichever shall first happen.
Since then, the term of copyright has been extended considerably in various jurisdictions. Many nations, including Canada and some of Europe, now use 50 years from the death of the author, and the US and EU have even higher limits.
In the United States, the law continues to evolve. The original US copyright law, in 1790, followed the Statute of Anne in granting a monopoly for only 14 years. Also, it regulated only printing, not the creation of derivative works. .
Since then, both the duration and the scope of copyright have greatly increased. A major revision in 1976 clarified many issues, addressed the issues of copyright in new media, and established the Copyright Tribunal for judging disputes. Copyrightable works generally include books, audio recordings, film and video, drawings and sometimes works of architecture.
The Sonny Bono Copyright Extension Act , passed in 1998, increased the duration of most US copyrights. Previously, it was 50 years after the death of the author, but the act raised this to the life of the author plus seventy years, or 95 years for works of corporate authorship.  Critics called it the "Mickey Mouse Protection Act" .
The Digital Millennium Copyright Act or DMCA of 1998 dealt with a number of issues, especially of concern to entertainment companies.  In particular, the DMCA makes it illegal to circumvent "technological protection measures" (see digital rights management) imposed by copyright holders, or to distribute any "circumvention device". This leads to complications; what happens when a "protection measure" impinges on fair use? Or when an alleged "device" is a piece of code, obviously not a "device" in a strict sense of that word and arguably a constitutionally protected form of free speech? There have been a number of court cases over this, notably the suits over the DeCSS code which breaks the usage control systems on DVD disks and the prosecution of Dimitri Sklyarov for breaking protection on Adobe e-books.
The World Trade Organization
The agreement establishing the WTO includes the Agreement on Trade-Related Aspects of Intellectual Property Rights, often referred to as the TRIPS Agreement. That sets minimum terms for copyright:
Whenever the term of protection of a work, other than a photographic work or a work of applied art, is calculated on a basis other than the life of a natural person, such term shall be no less than 50 years from the end of the calendar year of authorized publication, or, failing such authorized publication within 50 years from the making of the work, 50 years from the end of the calendar year of making. 
This leaves governments free to grant a longer term, as the US does, or to limit copyright to the life of the author or life+whatever.
The Anti-Counterfeiting Trade Agreement is under negotiation. Proponents say it is an essential piece of work, absolutely necessary to provide reasonable protection for intellectual property in a globalised economy.
Opponents have been vociferous about the secrecy of the negotiations and highly critical of some provisions which they see as a US-led attempt to extend the (in their view, hopelessly flawed) US DMCA worldwide. It is also seen as an instance of policy laundering. Some policies would be too controversial for a US administration to introduce at home; instead they first promote those policies as part of ACTA so that when they later introduce them, they can claim they are only working to comply with international agreements.
- "Copyright and wrong: Why the rules on copyright need to return to their roots", The Economist, April 8th 2010
- Thomas Macaulay (1841)
- Lawrence Lessig Free Culture
- Cooley Godward Kronish LLP (1 December 1998), The Digital Millennium Copyright Act and Other Recent Copyright Law Changes
- Lawrence Lessig (2001), "Copyright's First Amendment", UCLA Law Review
- TRIPS Agreement — SECTION 1: COPYRIGHT AND RELATED RIGHTS — Article 12 Term of Protection, 1994
- David Kravitz (November 2009), "Copyright Treaty Is Policy Laundering at Its Finest", Wired