The copyright law of the United States grants monopoly protection for "original works of authorship". With the stated purpose to promote art and culture, copyright law assigns a set of exclusive rights to authors: to make and sell copies of their works, to create derivative works, and to perform or display their works publicly. These exclusive rights are subject to a time limit, and generally expire 70 years after the author's death or 95 years after publication. In the United States, works published before January 1, 1926, are in the public domain.
United States copyright law was last generally revised by the Copyright Act of 1976, codified in Title 17 of the United States Code. The United States Constitution explicitly grants Congress the power to create copyright law under Article 1, Section 8, Clause 8, known as the Copyright Clause. Under the Copyright Clause, Congress has the power, "To promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries."
US copyright law traces its lineage back to the British Statute of Anne, which influenced the first US federal copyright law, the Copyright Act of 1790. The length of copyright established by the Founding Fathers was short, 14 years, plus the ability to renew it one time, for 14 more. 40 years later, the initial term was changed to 28 years. It was not until a full 180 years after its establishment that it was significantly extended beyond that, in Copyright Act of 1976 to "Either 75 years or the life of the author plus 50 years" and the Sonny Bono Copyright Term Extension Act of 1998 (also called the "Mickey Mouse Protection Act", because it prevented the copyright from expiring on the first commercial success of the cartoon character Mickey Mouse), which increased it even more, to 120 years, or the life of the author plus 70 years.
The Congress shall have Power [...] to promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries.
The goal of copyright law, as set forth in the Copyright Clause of the US Constitution, is "to promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries." This includes incentivizing the creation of art, literature, architecture, music, and other works of authorship. As with many legal doctrines, the effectiveness of copyright law in achieving its stated purpose is a matter of debate.
The United States copyright law protects "original works of authorship," fixed in a tangible medium including literary, dramatic, musical, artistic, and other intellectual works. This protection is available to both published and unpublished works. Copyright law includes the following types of works:
Copyright law protects the "expression" of an idea, but copyright does not protect the "idea" itself. This distinction is called the idea-expression dichotomy. The distinction between "idea" and "expression" is fundamental to copyright law. From the Copyright Act of 1976 (17 U.S.C. § 102):
In no case does copyright protection for an original work of authorship extend to any idea, procedure, process, system, method of operation, concept, principle, or discovery, regardless of the form in which it is described, explained, illustrated, or embodied in such work.
For example, a paper describing a political theory is copyrightable. The paper is the expression of the author's ideas about the political theory. The theory itself is just an idea, and is not copyrightable. Another author is free to describe the same theory in their own words without infringing on the original author's copyright.
Although fundamental, the idea-expression dichotomy is often difficult to put into practice. Reasonable people can disagree about where the unprotectable "idea" ends and the protectable "expression" begins. As Judge Learned Hand put it, "Obviously, no principle can be stated as to when an imitator has gone beyond copying the 'idea,' and has borrowed its 'expression.' Decisions must therefore inevitably be ad hoc."
Mere facts are not copyrightable. However, compilations of facts are treated differently, and may be copyrightable material. The Copyright Act, § 103, allows copyright protection for "compilations", as long as there is some "creative" or "original" act involved in developing the compilation, such as in the selection (deciding which facts to include or exclude), and arrangement (how facts are displayed and in what order). Copyright protection in compilations is limited to the selection and arrangement of facts, not to the facts themselves.
The Supreme Court decision in Feist Publications, Inc., v. Rural Telephone Service Co. clarified the requirements for copyright in compilations. The Feist case denied copyright protection to a "white pages" phone book (a compilation of telephone numbers, listed alphabetically). In making this ruling, the Supreme Court rejected the "sweat of the brow" doctrine. That is, copyright protection requires creativity, and no amount of hard work ("sweat of the brow") can transform a non-creative list (like an alphabetical listing of phone numbers) into copyrightable subject matter. A mechanical, non-selective collection of facts (e.g., alphabetized phone numbers) cannot be protected by copyright.
Copyright protects artistic expression. Copyright does not protect useful articles, or objects with some useful functionality. The Copyright Act states:
A "useful article" is an article having an intrinsic utilitarian function that is not merely to portray the appearance of the article or to convey information. An article that is normally a part of a useful article is considered a "useful article".
"the design of a useful article, as defined in this section, shall be considered a pictorial, graphic, or sculptural work only if, and only to the extent that, such design incorporates pictorial, graphic, or sculptural features that can be identified separately from, and are capable of existing independently of, the utilitarian aspects of the article."
However, many industrial designers create works that are both artistic and functional. Under these circumstances, copyright law only protects the artistic expression of such a work, and only to the extent that the artistic expression can be separated from its utilitarian function.
In 2017, the US Supreme Court granted certiorari in the case Star Athletica, L. L. C. v. Varsity Brands, Inc. to determine when a "pictorial, graphic, or sculptural feature" incorporated into a useful article is eligible for copyright protection, holding that such features are eligible for copyright protection "only if the feature (1) can be perceived as a two- or three-dimensional work of art separate from the useful article and (2) would qualify as a protectable pictorial, graphic, or sculptural work--either on its own or fixed in some other tangible medium of expression--if it were imagined separately from the useful article into which it is incorporated." Star Athletica began as a suit by Varsity Brands against Star Athletica for infringing the copyright of five cheerleader uniform designs. Applying its new test to the cheerleader uniform designs, the court said:
First, one can identify the decorations as features having pictorial, graphic, or sculptural qualities. Second, if the arrangement of colors, shapes, stripes, and chevrons on the surface of the cheerleading uniforms were separated from the uniform and applied in another medium--for example, on a painter's canvas--they would qualify as "two-dimensional . . . works of . . . art". And imaginatively removing the surface decorations from the uniforms and applying them in another medium would not replicate the uniform itself. Indeed, respondents have applied the designs in this case to other media of expression--different types of clothing--without replicating the uniform. The decorations are therefore separable from the uniforms and eligible for copyright protection.
This produces a relatively low threshold for pictorial, graphic, or sculptural features on useful articles to be eligible for copyright protection, which one commentator clearly highlighted: the Star Athletica decision "really has ensured that all but the subtlest graphic designs will be able to gain copyright protection...once we determine that the designs 'hav[e] ... graphic ... qualities ... [and could be] applied ... on a painter's canvas,' the test for copyrightability is met."
Works created by the federal government are not copyrightable. 17 U.S.C. § 105. This restriction on copyright applies to publications produced by the United States Government, and its agents or employees within the scope of their employment. The specific language is as follows:
Copyright protection under this title is not available for any work of the United States Government, but the United States Government is not precluded from receiving and holding copyrights transferred to it by assignment, bequest, or otherwise.
A "work of the United States Government" is defined in 17 U.S.C. § 101 as "a work prepared by an officer or employee of the United States Government as part of that person's official duties". Note that government contractors are generally not considered employees, and their works may be subject to copyright. Likewise, the US government can purchase and hold the copyright to works created by third parties.
The government may restrict access to works it has produced through other mechanisms. For instance, confidential or secret materials are not protected by copyright, but are restricted by other applicable laws. However, even in case of non-secret materials there are specific prohibitions against automatic access to work otherwise covered under 17 U.S.C. § 105 for commercial purposes.
Federal, state, and local statutes and court decisions are in the public domain and are ineligible for copyright, a concept known as the government edicts doctrine. It is not difficult to see the motivations behind this:
The citizens are the authors of the law, and therefore its owners, regardless of who actually drafts the provisions, because the law derives its authority from the consent of the public, expressed through the democratic process.
Three key Supreme Court cases established this government edicts doctrine: Wheaton v. Peters (1834), Banks v. Manchester (1888), and Callaghan v. Myers (1888). The doctrine was codefied into the United States Code at 17 U.S.C. § 105 via the Copyright Act of 1976. The Copyright Office upholds this doctrine within its own regulations:
As a matter of longstanding public policy, the U.S. Copyright Office will not register a government edict that has been issued by any state, local, or territorial government, including legislative enactments, judicial decisions, administrative rulings, public ordinances, or similar types of official legal materials. Likewise, the Office will not register a government edict issued by any foreign government or any translation prepared by a government employee acting within the course of his or her official duties.
The Supreme Court has also ruled that annotated versions of statutes or court decisions at the federal, state, and local level, when such annotations are done by members of the government as part of their duties, are ineligible for copyright in Georgia v. Public.Resource.Org, Inc. (2020).
There are six basic rights protected by copyright. The owner of copyright has the exclusive right to do and to authorize others to do the following:
The initial owner of the copyright to a work is the author, unless that work is a "work made for hire".
If a work is not a work for hire, then the author will be the initial copyright owner. The author generally is the person who conceives of the copyrightable expression and "fixes" it in a "tangible medium of expression." Special rules apply when multiple authors are involved:
Three types of transfers exist for copyrighted works.
The first two, assignment and exclusive licenses, require the transfer to be in writing. Nonexclusive licenses need not be in writing and they may be implied by the circumstances. Transfers of copyright always involve one or more of the exclusive rights of copyright. For instance, a license may provide a right to perform a work, but not to reproduce it or to prepare a derivative work (adaptation right).
The terms of the license is governed by the applicable contract law, however there is substantial academic debate about to what extent the Copyright Act preempts state contract law principles.
An author, after transferring a copyright, can terminate the transfer under certain circumstances. This right to terminate the transfer is absolute and cannot be waived.
For works published since 1978, copyrights may revert to the original author after 35 years. Title 17, United States Code, Section 203 states that the author must write a letter requesting a termination of the original copyright grant at least two years before the effective termination date.
Title 17, United States Code, Section 108 places limitations on exclusive copyrights for the purposes of certain limited reproduction by a public library or an archive. Title 17, United States Code, Section 107 also places statutory limits on copyright which are commonly referred to as the fair use exception.
Copyright is automatically granted to the author of an original work (that otherwise meets the basic copyright requirements, discussed above). Registration is not necessary. However, registration amplifies a copyright holder's rights in a number of ways. Registration is required before a lawsuit can be filed, and registration creates the possibility for enhanced "statutory" damages.
A copyright can be registered online at the US Copyright Office's website. The Copyright Office reviews applications for obvious errors or lack of copyrightable subject matter and then issues a certificate of registration. The Copyright Office does not compare the author's new work against a collection of existing works or otherwise check for infringement.
The United States Copyright Office requires a deposit copy of the work for which copyright registration is sought. Deposits can be made through the Copyright Office's eCO System. This deposit requirement serves two purposes. First, if a copyright infringement lawsuit arises, the owner may prove that the material that is infringed is exactly the same material for which the owner has secured a registration. Second, this requirement helps the Library of Congress build its collection of works.
Failure to comply with the deposit requirement, as modified by Copyright Office regulations, is punishable by fine, but does not result in forfeiture of copyright.
The use of copyright notices is optional. The Berne Convention, amending US copyright law in 1989, makes copyright automatic. However, the lack of notice of copyright using these marks may have consequences in terms of reduced damages in an infringement lawsuit--using notices of this form may reduce the likelihood of a defense of "innocent infringement" being successful.
Copyright protection generally lasts for 70 years after the death of the author. If the work was a "work for hire", then copyright persists for 120 years after creation or 95 years after publication, whichever is shorter. For works created before 1978, the copyright duration rules are complicated. However, works published before January 1, 1926 (other than sound recordings) have made their way into the public domain.
For works published or registered before 1978, the maximum copyright duration is 95 years from the date of publication, if copyright was renewed during the 28th year following publication. Copyright renewal has been automatic since the Copyright Renewal Act of 1992.
For works created before 1978, but not published or registered before 1978, the standard §302 copyright duration of 70 years from the author's death also applies. Prior to 1978, works had to be published or registered to receive copyright protection. Upon the effective date of the 1976 Copyright Act (which was January 1, 1978) this requirement was removed and these unpublished, unregistered works received protection. However, Congress intended to provide an incentive for these authors to publish their unpublished works. To provide that incentive, these works, if published before 2003, would not have their protection expire before 2048.
All copyrightable works published in the United States before 1926 are in the public domain; works created but not published or copyrighted before January 1, 1978 may be protected until 2047. For works that received their copyright before 1978, a renewal had to be filed in the work's 28th year with the Copyright Office for its term of protection to be extended. The need for renewal was eliminated by the Copyright Renewal Act of 1992, but works that had already entered the public domain by non-renewal did not regain copyright protection. Therefore, works published before 1964 that were not renewed are in the public domain.
Before 1972, sound recordings were not subject to federal copyright, but copying was nonetheless regulated under various state torts and statutes, some of which had no duration limit. The Sound Recording Amendment of 1971 extended federal copyright to recordings fixed on or after February 15, 1972, and declared that recordings fixed before that date would remain subject to state or common law copyright. Subsequent amendments had extended this latter provision until 2067. As a result, older sound recordings were not subject to the expiration rules that applied to contemporary visual works. Although these could have entered the public domain as a result of government authorship or formal grant by the owner, the practical effect has been to render public domain audio virtually nonexistent.
This situation has changed with the 2018 enactment of the Music Modernization Act, which extended federal copyright protection to all sound recordings, regardless of their date of creation, and preempted state copyright laws on those works. Under the Act, the first sound recordings to enter the public domain will be those fixed before 1923, which will enter the public domain on January 1, 2022. Recordings fixed between 1923 and February 14, 1972 will be phased into the public domain in the following decades. Specifically, works fixed 1923-1946 are public after 100 years and works fixed 1947-1956 after 110 years of fixation. Works fixed 1 January 1957 - 14 February 1972 will all become public on 15 February 2067.
In May 2016, Judge Percy Anderson ruled in a lawsuit between ABS Entertainment and CBS Radio that "remastered" versions of pre-1972 recordings can receive a federal copyright as a distinct work due to the amount of creative effort expressed in the process. The Ninth Circuit appeals court reversed the decision in favor of ABS Entertainment.
United States copyright law includes numerous defenses, exceptions, and limitations. Some of the most important include:
Fair use is the use of limited amounts of copyrighted material in such a way as to not be an infringement. It is codified at 17 U.S.C. § 107, and states that "the fair use of a copyrighted work ... is not an infringement of copyright." The section lists four factors that must be assessed to determine whether a particular use is fair. There are no bright-line rules regarding fair use and each determination is made on an individualized case-by-case basis.
In addition to these four factors, the statute also allows courts to consider any other factors that may be relevant to the fair use analysis. Courts evaluate fair use claims on a case-by-case basis, and the outcome of any given case depends on the specific facts of that case. There is no formula to ensure that a predetermined percentage or amount of a work--or specific number of words, lines, pages, copies--may be used without permission.
The justification of the fair use doctrine turns primarily on whether, and to what extent, the challenged use is transformative. "The use must be productive and must employ the quoted matter in a different manner or for a different purpose from the original. A quotation of copyrighted material that merely repackages or republishes the original is unlikely to pass the test.... If, on the other hand, the secondary use adds value to the original--if the quoted matter is used as raw material, transformed in the creation of new information, new aesthetics, new insights and understandings--this is the very type of activity that the fair use doctrine intends to protect for the enrichment of society."
The Copyright Office provides a searchable list of fair use case law.
Although a parody can be considered a derivative work, and thus within the exclusive rights of the copyright owner, it may qualify as "fair use." Parodies are not automatically fair use. The Supreme Court of the United States stated that parody (transformative) "is the use of some elements of a prior author's composition to create a new one that, at least in part, comments on that author's works." That commentary function provides some justification for use of the older work; in contrast, a satire (exaggerated) (which is not targeted at the work borrowed from) does not require use of the original work to make its point. (See Campbell v. Acuff-Rose Music, Inc.).
Copyright infringement occurs when someone violates one of the exclusive rights listed in 17 USC 106. Commonly, this involves someone creating or distributing a "copy" of a protected work that is "substantially similar" to the original version.
Infringement requires copying. If two people happen to write exactly the same story, without knowledge of the other, there is no infringement.
A copyright owner may bring a copyright infringement lawsuit in federal court. Federal courts have exclusive subject-matter jurisdiction over copyright infringement cases. That is, an infringement case may not be brought in state courts. (With an exception for works not protected under Federal law, but are protected under state law, e.g. state laws prohibiting copying of sound recordings made before February 15, 1972.) Note that the Copyright Office handles copyright registrations, but it does not adjudicate copyright infringement disputes.
To bring a copyright infringement lawsuit, a copyright holder must establish ownership of a valid copyright and the copying of constituent elements of the work that are original. The copyright owner must also establish both (a) actual copying and (b) improper appropriation of the work. The copyright owner, as plaintiff, bears the burden of establishing these three elements of the prima facie case for infringement.
A plaintiff establishes ownership by authorship (by the plaintiff itself or by someone who assigned rights to the plaintiff) of (1) an original work of authorship that is (2) fixed in a tangible medium (e.g. a book, musical recording, etc.).
Registration is not required to establish copyright protection, but registration is necessary before bringing a lawsuit. Registration is also useful because it creates a presumption of a valid copyright, it allows the plaintiff to collect enhanced "statutory damages", and to be eligible for an award of attorney fees.
A plaintiff establishes "actual copying" with direct or indirect evidence. Direct evidence is satisfied either by a defendant's admission to copying or the testimony of witnesses who observed the defendant in the act. More commonly, a plaintiff relies on circumstantial or indirect evidence. A court will infer copying by a showing of a "striking similarity" between the copyrighted work and the alleged copy, along with a showing of both access and use of that access. A plaintiff may establish "access" by proof of distribution over a large geographical area, or by eyewitness testimony that the defendant owned a copy of the protected work. Access alone is not sufficient to establish infringement. The plaintiff must show a similarity between the two works, and the degree of similarity will affect the probability that illicit copying in fact occurred in the court's eyes. Even then, the plaintiff must show that the copying amounted to improper appropriation. Indeed, the United States Supreme Court has held that not all copying constitutes infringement and a showing of misappropriation is necessary.
A copyrighted work may contain elements which are not copyrightable, such as facts, ideas, themes, or content in the public domain. A plaintiff alleging misappropriation must first demonstrate that what the defendant appropriated from the copyrighted work was protectible. Second, a plaintiff must show that the intended audience will recognize substantial similarities between the two works. The intended audience may be the general public, or a specialized field. The degree of similarity necessary for a court to find misappropriation is not easily defined. Indeed, "the test for infringement of a copyright is of necessity vague."
Two methods are used to determine if unlawful appropriation has occurred: the "subtractive method" and the "totality method".
The subtractive method, also known as the "abstraction/subtraction approach" seeks to analyze what parts of a copyrighted work are protectible and which are not. The unprotected elements are subtracted and the fact finder then determines whether substantial similarities exist in the protectible expression which remains. For instance, if the copyright holder for West Side Story alleged infringement, the elements of that musical borrowed from Romeo and Juliet would be subtracted before comparing it to the allegedly infringing work because Romeo and Juliet exists in the public domain.
The totality method, also known as the "total concept and feel" approach takes the work as a whole with all elements included when determining if a substantial similarity exists. This was first formulated in Roth Greeting Cards v. United Card Co. (1970). The individual elements of the alleged infringing work may by themselves be substantially different from their corresponding part in the copyrighted work, but nevertheless taken together be a clear misappropriation of copyrightable material.
Modern courts may sometimes use both methods in its analysis of misappropriation. In other instances, one method may find misappropriation while the other would not, making misappropriation a contentious topic in infringement litigation.
A successful copyright infringement plaintiff may seek both "injunctive relief" and monetary damages. As of 2019, the United States Supreme Court has held that a copyright holder must register his copyright with the U.S. copyright office before he may seek any judicial remedies for infringement.
Injunctions: Copyright Act § 502 authorizes courts to grant both preliminary and permanent injunctions against copyright infringement. There are also provisions for impounding allegedly infringing copies and other materials used to infringe, and for their destruction.
Damages and/or Profits: Copyright Act § 504 gives the copyright owner a choice of recovering: (1) their actual damages and any additional profits of the defendant; or (2) statutory damages.
However, Title 17 United States Code §411(a) states that a civil action to enforce a copyright claim in a US work cannot be made until the work has been registered with the U.S. Copyright Office, with a narrow exception if the claim was filed and rejected by the Copyright Office. In 2019, the U.S. Supreme Court decided that §411(a) requires that a lawsuit cannot be initiated until the Copyright Office has processed, not merely received, the application.
Both temporary and permanent injunctions are available to prevent or restrain infringement of a copyright. An "injunction" is a court order directing the defendant to stop doing something (e.g., stop selling infringing copies). One form of equitable relief that is available in copyright cases is a seizure order. At any time during the lawsuit, the court may order the impoundment of any and all copies of the infringing products. The seizure order may include materials used to produce such copies, such as master tapes, film negatives, printing plates, etc. Items that are impounded during the course of the lawsuit can, if the plaintiff wins, be ordered destroyed as part of the final decree.
A copyright holder can also seek monetary damages. Injunctions and damages are not mutually exclusive. One can have injunctions and no damages, or damages and no injunctions, or both injunctions and damages. There are two types of damages: actual damages and profits, or statutory damages.
The copyright owner may recover the profits he or she would have earned absent the infringement (actual damages) and any profits the infringer might have made as a result of the infringement but that are not already considered in calculating actual damages. To recover actual damages, the plaintiff must prove to the court that, in the absence of the infringement, the plaintiff would have been able to make additional sales, or perhaps been able to charge higher prices, and that this would have resulted in profits given the owner's cost structure. In some cases, the profits earned by the infringer exploiting the copyrighted material may exceed those earned by or potentially available to the owner. In these circumstances, the copyright owner can recover the infringer's profits if he or she can demonstrate a nexus between the profits and the infringing use.
Statutory damages are available as an alternative to actual damages and profits. If the copyright was registered either (a) within three months of publication or (b) before the infringement, then the plaintiff is eligible to seek statutory damages. Statutory damages can be awarded by the court within the range of $750 to $30,000, but this can be lowered if the infringement is deemed inadvertent, or increased significantly if the infringement is willful.
Statutory damages are sometimes preferable for the plaintiff if actual damages and profits are either too small, or too difficult to prove, or both. There are, however, situations where statutory damages are not available. 17 U.S.C. § 412 provides:
Statutory damages are calculated per work infringed. According to clause (1) of Title 17, U.S.C. Section 504(c), statutory damages range from $750 per work to $30,000 per work, with two principal exceptions:
Damages in copyright cases can be very high. In Lowry's Reports, Inc. v. Legg Mason Inc., a 2003 lawsuit between a publisher of stock analysis newsletters against a company that buys one copy of the newsletters and makes multiple copies for use in-house, the jury awarded damages - actual damages for some newsletters and statutory damages for other newsletters - totaling $20 million.
Cost and attorney fees: Copyright Act § 505 permits courts, in their discretion, to award costs against either party and to award reasonable attorney fees to the prevailing party. The court may (but is not required to) award to the "prevailing party" reasonable attorney's fees. This applies to both a winning plaintiff (copyright owner) and a winning defendant (accused infringer). However, attorney's fees award is not available against the government. Like statutory damages, attorney's fees are not available if the work infringed is not registered at the time of infringement.
In addition to the civil remedies, the Copyright Act provides for criminal prosecution in some cases of willful copyright infringement. There are also criminal sanctions for fraudulent copyright notice, fraudulent removal of copyright notice, and false representations in applications for copyright registration. The Digital Millennium Copyright Act imposes criminal sanctions for certain acts of circumvention and interference with copyright management information. There are not criminal sanctions for violating the rights of attribution and integrity held by the author of a work of visual art.
Criminal penalties for copyright infringement include:
Felony penalties for first offenses begin at seven copies for audiovisual works, and one hundred copies for sound recordings.
The US government, its agencies and officials, and corporations owned or controlled by it, are subject to suit for copyright infringement. All infringement claims against the U.S. that did not arise in a foreign country must be filed with the United States Court of Federal Claims within three years of the infringing action. Claims filed in the wrong court are dismissed for lack of subject-matter jurisdiction. The government and its agencies are also authorized to settle the infringement claims out of court.
The states have sovereign immunity provided by the Eleventh Amendment to the United States Constitution, which bars most forms of lawsuits against states in federal courts, but can be abrogated in certain circumstances by Congress. The Copyright Remedy and Clarification Act of 1990 (CRCA) states in part that states are liable to copyright infringement "in the same manner and to the same extent as any nongovernmental entity" and also that states and state entities and officials "shall not be immune, under the Eleventh Amendment to the Constitution of the United States or under any other doctrine of sovereign immunity, from suit in Federal Court by any person" alleging copyright infringement.:1 The CRCA has been declared unconstitutional by several federal courts.,:4 and this was upheld by the US Supreme Court on March 23, 2020.
Works in the public domain are free for anyone to copy and use. Strictly speaking, the term "public domain" means that the work is not covered by any intellectual property rights at all (copyright, trademark, patent, or otherwise). However, this article discusses public domain with respect to copyright only.
A work may enter the public domain in a number of different ways. For example, (a) the copyright protecting the work may have expired, or (b) the owner may have explicitly donated the work to the public, or (c) the work is not the type of work that copyright can protect.
The "orphan works" problem arose in the United States with the enactment of the Copyright Act of 1976, which eliminated the need to register copyrighted works, instead declaring that all "original works of authorship fixed in any tangible medium of expression" fall into copyright status. The elimination of registration also eliminated a central recording location to track and identify copyright-holders. Consequently, potential users of copyrighted works, e.g., filmmakers or biographers, must assume that many works they might use are copyrighted. Where the planned use would not be otherwise permitted by law (for example, by fair use), they must themselves individually investigate the copyright status of each work they plan to use. With no central database of copyright-holders, identifying and contacting copyright-holders can sometimes be difficult; those works that fall into this category may be considered "orphaned".
To qualify as a work of 'authorship' a work must be created by a human being.... Works that do not satisfy this requirement are not copyrightable. The Office will not register works produced by nature, animals, or plants.The Compendium lists several examples of such ineligible works, including "a photograph taken by a monkey" and "a mural painted by an elephant".