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Introduction to Intellectual Property

4.9 Trademark Infringement

Introduction to Intellectual Property4.9 Trademark Infringement

Learning Objectives

After completing this section, you will be able to

  • Identify the factors involved in trademark infringement.
  • Understand the basis for determining similarity.

Trademark Infringement and Remedies

Before reading this section, please watch the overview video below covering similarity, market confusion, vicarious infringement, and getting back what’s yours.

The purpose of trademarks is to enable consumers to distinguish the source of products and services as well as help businesses defend the quality and reputation of those goods. Trademarks benefit society by protecting consumers and businesses alike, and by preventing confusion in the marketplace. This principle lies at the heart of the trademark system.

It is also the basis on which the courts rule on claims of trademark infringement. The most common way that trademark infringement causes confusion is through similarity. In the words of the Lanham Act, no trademark may be registered “which so resembles” another name or mark that it will be likely “to cause confusion, or to cause mistake, or to deceive.”xl

To determine similarity, the mark must be evaluated as a whole rather than through its individual components. This is important because there are only a limited number of parts—words, names, shapes, symbols, or devices—that can be used separately or together to create a unique and distinctive trademark that indicates the origin of goods.

The courts generally look at five key factors to determine if a defendant’s use of your mark is likely to cause confusion among consumers.

The two most important are:
  • The similarity in the overall impression created by the two marks (including the marks’ look, phonetic similarities, and underlying meanings)
  • The similarities of the goods and services involved.
But the court also looks at three other factors:
  • The strength of your mark.
  • Any evidence of actual confusion by consumers.
  • The intent of the defendant in adopting its mark.

The basis for determining similarity, again, is not an assessment of the similarity between each component of two trademarks but of their totality as seen and experienced by the consumer. And the key test for similarity is resemblance, not sameness. In short, two marks do not have to be exact mirror images of each other to be legally similar. According to a 2003 decision by the U.S. Court of Appeals for the Federal Circuit, “Similarity is not a binary factor but is a matter of degree."xli Each and every attribute of a mark need not be replicated exactly by those of another mark to be deemed similar. But the more one mark’s attributes are similar to those of another, the greater the likelihood that there is legal similarity between the marks as a whole.

The social networking site LinkedIn, for example, sports a logo made up of the joined words “Linked” and “in” displayed in a white font with the “in” component surrounded by a blue colored square with rounded edges. If a new networking site for professionals was launched that featured a logo with the same words except that the “in” component was surrounded by a red colored square, there would likely be enough similarity between the two logos to justify a case for infringement. The colors of one component of the logo may be different, but when the concept, wording, font style, and design are considered as a whole, any judge or jury would probably find the similarity between the marks so substantial as to constitute infringement.

But similarity is not the only basis for assessing infringement. The question is also whether any similarity between marks is likely to cause confusion in the minds of consumers. This takes into account such factors as the similarity of the goods and services on which the two marks are being used. If a company that made metal chains called itself “LinkedIn,” that would less likely cause consumers to believe that the chains came from the same source as the social networking site, because the manufacture of chains is a very different line of business than running a social networking site.

An entity can be guilty of contributory infringement if it intentionally encourages the infringement of a valid mark by a third party. One can also be liable for contributory infringement if one continues to produce or distribute a product with knowledge that the beneficiary is infringing a mark. As the Supreme Court held in the 1982 case Inwood Labs., Inc. v. Ives Labs., Inc. , “If a manufacturer or distributor intentionally induces another to infringe a trademark, or if it continues to supply its product to one whom it knows or has reason to know is engaging in trademark infringement, the manufacturer or distributor is contributorily responsible for any harm done as a result of the deceit.”xlii

If a manufacturer or distributor intentionally induces another to infringe a trademark, or if it continues to supply its product to one whom it knows or has reason to know is engaging in trademark infringement, the manufacturer or distributor is contributorily responsible for any harm done as a result of the deceit.”xliii

-Inwood Labs., Inc. v. Ives Labs., Inc.

Another type of infringement is vicarious infringement. The definition of vicarious infringement is somewhat convoluted, but Cornell University’s Legal Information Institute describes it thusly:

“A person may be held liable for the infringing acts committed by another if he or she had the right and ability to control the infringing activities and had a direct financial interest in such activities. The existence of direct infringement is required to establish a claim of vicarious infringement; however, it is not necessary for the alleged infringer to have intent or knowledge of the infringement.”xliv

Vicarious infringement most often occurs on Internet sites that allow outside parties to post or upload files. One such example was Sega Enters., Ltd. v. MAPHIA ., in which third parties uploaded unauthorized games that displayed the Sega mark to the Maphia site with the knowledge and consent of—and to the profit of—Maphia owners.

Finally, there is a form of harm called trademark dilution, which is described by the International Trademark Association as “the weakening of a famous mark’s ability to identify and distinguish goods or services, regardless of competition in the marketplace or the likelihood of confusion. Dilution typically occurs as the result of blurring or tarnishment of the famous mark. . . . The concept of dilution developed from the idea that because some marks are so well-known and famous, they deserve an extra level of protection beyond the likelihood-of-confusion analysis. Dilution theory seeks to prevent the coexistence of a mark that is sufficiently similar to a famous mark, regardless of the goods and/or services associated with the allegedly diluting mark.”

The Federal Trademark Dilution Act of 1995 and the Federal Dilution Revision Act of 2006 created a federal cause of action for trademark dilution that is separate from infringement. Generally speaking, an owner of a trademark eligible for dilution protection can prevent another company from using that mark no matter how dissimilar the goods and services of the two companies are. That makes dilution protection potentially broader in scope than infringement protection. After the 2006 revision, however, only marks that are “widely recognized by the general consuming public of the United States” are eligible for dilution protection, which means that only a very small percentage of trademarks used in the United States—undoubtedly less than 1 percent—qualify for that protection. Google has protection against dilution. Your local dry cleaner does not.


  • xl See 15 U.S.C. § 1052 Retrieved from
  • xli In re Coors Brewing Co., Fed. Cir. 2003 Retrieved from:
  • xlii Inwood Labs., Inc. v. Ives Labs., Inc., 456 U.S. 844, 854 (1982) Retrieved from
  • xliii Inwood Labs., Inc. v. Ives Labs., Inc., 456 U.S. 844, 854 (1982) Retrieved from
  • xliv Derived from:
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