Copyright Infringement and the Substantial Similarity Test

What counts as infringement

The Copyright Act gives the owner exclusive rights to reproduce the work, prepare derivative works, distribute copies, perform the work publicly, display it publicly and, for sound recordings, perform them by digital audio transmission (17 U.S.C. 106). Anyone who violates one of these rights is an infringer (17 U.S.C. 501(a)).

Copyright protects an original work fixed in a tangible medium (17 U.S.C. 102(a)). The Copyright Office says protection exists from the moment the work is created and fixed. Registration is not needed for protection, but it is needed before a lawsuit.

What the owner must prove

The Supreme Court states two elements: ownership of a valid copyright, and copying of constituent elements of the work that are original (Feist Publications, Inc. v. Rural Telephone Service Co., 499 U.S. 340 (1991)).

Substantial similarity is a doctrine that courts developed in their decisions. No single formula measures it, and the wording of the test varies between federal circuits, so the test that applies can depend on where the case is filed.

Ideas, facts and expression

Copyright does not extend to an idea, procedure, process, system, method of operation, concept, principle or discovery, however it is described or embodied in a work (17 U.S.C. 102(b)). Facts are not copyrightable (Feist).

A poem about the beauty of spring shows the line. The theme of spring is open to everyone. The poet’s specific words, structure and imagery are the expression that copyright protects.

Because ideas and facts are not protected, similarity in those elements does not show infringement. A court compares the protected expression in the two works.

Substantial similarity and fair use are different questions

Substantial similarity is part of the owner’s proof. It asks whether the defendant’s work is alike enough to the owner’s protected expression to support a finding of copying.

Fair use is a defense. Section 107 allows uses such as criticism, comment, news reporting, teaching, scholarship or research, and weighs four factors: the purpose and character of the use, the nature of the work, the amount and substantiality of the portion used, and the effect on the market for the work.

A work can be substantially similar to another and still be a fair use. A court decides fair use on the four factors, case by case.

Before you sue: registration, deadlines and remedies

These rules decide whether and how an owner can sue:

• Registration: a U.S. work must be registered before an infringement suit (17 U.S.C. 411(a)). The Supreme Court held that registration happens when the Copyright Office registers the work, not when the owner applies (Fourth Estate Public Benefit Corp. v. Wall-Street.com, LLC, No. 17-571, decided 4 March 2019).
• Time limit: a civil claim must be filed within three years after it accrued (17 U.S.C. 507(b)).
• Damages: the owner may recover actual damages and the infringer’s profits, or elect statutory damages (17 U.S.C. 504). Statutory damages are $750 to $30,000 for any one work. The court may raise the award to $150,000 for willful infringement or lower it to $200 for innocent infringement (17 U.S.C. 504(c)).
• Early registration: statutory damages and attorney’s fees are not available when the infringement began before registration, unless a published work was registered within three months after first publication (17 U.S.C. 412).
• Costs and fees: the court may award full costs and a reasonable attorney’s fee to the prevailing party (17 U.S.C. 505).

If someone copies your work: first steps

1. Save the evidence: the original file with its date, and copies or screenshots of the other work with the web address and the date you captured it.
2. Check whether your work is registered and when. The dates affect statutory damages and attorney’s fees.
3. If the copy is online, consider a notice to the host under 17 U.S.C. 512(c)(3). The notice needs a signature, identification of your work and of the material, your contact details, a good-faith statement, and a statement under penalty of perjury that the notice is accurate and you are authorized to act.
4. Calculate the three-year limit from the date the claim accrued.
5. Have a lawyer compare the two works and review fair use before you send a demand letter or file suit.