Enforcing Intellectual Property Protections

A trademark infringement suit requires the proof of two elements. First, the plaintiff must prove that their mark is eligible for protection. This is where registration becomes very valuable, as it provides a rebuttable presumption that the mark is protectable. Second, the plaintiff must show that the allegedly infringing mark is likely to cause consumer confusion. If two marks are so similar that a reasonable consumer will not be able to discern the true source of the goods the marks are placed on, then this element will be met. There are a wide variety of factors used across federal district courts to determine the likelihood of consumer confusion. The most famous factors are called the Polaroid factors: strength of the plaintiff’s mark, similarity of the marks, similarity of the products/services, likelihood that the plaintiff will enter the defendant’s area of products/services, the defendant’s intent in using the mark, evidence of actual consumer confusion, the sophistication of the buyers of the respective products/services, and the quality of the defendant’s products/services.

There are several common defenses to a trademark infringement suit. These include fair use, expressive use, abandonment, assignment in gross, naked licensing, the first sale doctrine, and laches.


A copyright infringement suit also requires the proof of two elements. First, the plaintiff must prove ownership over the work in question. Again, registration can provide a presumption of ownership. Second, the plaintiff must show that the defendant violated one of the plaintiff’s exclusive rights in that work. These exclusive rights are laid out in the Copyright Act and include the right to reproduce or copy the work, the right to prepare derivative works, the right to distribute the work, the right to perform a work publicly, the right to display a work publicly, and the right to perform a work publicly by digital audio transmission. This last right only applies if the work is a sound recording.

The most common defenses to a copyright infringement suit include fair use and the innocent infringer defense. Fair use is assessed by considering four factors, found in section 107 of the Copyright Act. These factors are: the nature and character of the use, the nature of the copyrighted work, the amount or substantiality of the portion used, and the effect of the use on the potential market for, or value of the original work. While the balancing of these factors is far too complex to explore in this chapter, the factors weigh towards a finding of fair use when the use is not for profit, the copyrighted work is educational in nature, a minimal portion of the work is used, and the allegedly infringing work does not act as a market substitute for the original work. As previously mentioned, the innocent infringer defense is not available to a defendant if the work properly provided notice that a copyright was being claimed by the plaintiff.


A patent infringement suit follows the same two-element requirement of the other forms of intellectual property. First, the plaintiff must prove ownership of the patent that is allegedly being infringed upon. Second, the plaintiff must show that their rights are being infringed upon. This requires three sub-elements: the identity of the alleged infringer, the specific act or acts of infringement, and the similarity of the infringing item to the patented item.


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To the extent possible under law, Samantha Prince has waived all copyright and related or neighboring rights to Entrepreneurship Law: Company Creation, except where otherwise noted.