In the ever-evolving landscape of intellectual property (IP) law, “dupe” or “knockoff” lawsuits have become a significant concern for brands striving to protect their unique designs and brands. As an IP attorney, I have witnessed firsthand the complexities and challenges that arise in these cases.
As a recent example, on June 27, 2025, Lululemon filed a lawsuit in United States District Court in California against Costco for selling and, in one case, manufacturing knockoffs of its Scuba sweatshirts, Define jackets, and ABC pants. Lululemon alleges that Costco’s in-house Kirkland Signature brand infringes on its trademarks, trade dress and design patents, and is causing “significant harm” to its brand. The company is seeking to recover damages for lost profits and to stop Costco’s production and marketing of the copied items.
According to Lululemon, an “ordinary observer” would not be able to tell the difference between the two brands, but Costco’s products cost significantly less than Lululemon clothing. For example, a Lululemon Scuba hoodie sells between $99 to $118, whereas the Costco “knockoff” item costs $8. Lululemon alleges that Costco is “known to use manufacturers of popular branded products for its own KIRKLAND® ‘private label’ products” and that this practice could cause consumers to believe Kirkland products are made by the same suppliers of the original items. The Complaint claims Costco “does not dispel this ambiguity.” Of course, however, the “knockoff” items do not include Lululemon’s logo, which is a primary reason that many consumers purchase Lululemon products, i.e. for the name value associated with the Lululemon brand.
We will keep an eye on this case for any new developments.
Legal Strategies and Implications
In dupe lawsuits, the legal strategies employed can vary significantly depending on the nature of the alleged infringement and the IP rights impacted. Common strategies include:
- Patent and Trademark Enforcement: Companies should ensure that their patents and trademarks are up-to-date and enforceable. This involves regular audits of IP portfolios and taking swift legal action against infringers through cease-and-desist letters and, if necessary, lawsuits.
- Trade Dress Protection: For products with distinctive designs, trade dress protection can be a valuable tool. This requires demonstrating that the design is non-functional and has acquired secondary meaning in the marketplace.
- Consumer Confusion Analysis: In trademark cases, proving consumer confusion is often a key element. Companies should gather evidence, such as customer complaints, to support their claims.
Insights for Business Owners
To protect their intellectual property effectively, companies should consider the following steps:
- Conduct Comprehensive IP Audits: Regularly review and update IP portfolios to ensure all assets are protected.
- Register Trademarks and Patents: Secure legal protection for key elements of your brand, including logos, designs, and inventions.
- Monitor the Market: Implement a system to detect potential infringements and take prompt action to address them.
- Educate Employees: Ensure that employees understand the importance of IP protection and are vigilant in identifying potential threats.
In conclusion, dupe lawsuits present significant challenges for brands, but with the right legal strategies and proactive measures, companies can safeguard their intellectual property and maintain their competitive edge.