The first post in this series covered recommended strategies for developing robust trademark usage policies and practices, particularly for common law trademark holders. 

In addition to properly using a mark, all trademark owners must be prepared to prevent and address the unauthorized or improper use of potentially conflicting marks by third parties. This post will cover options for common law trademark owners to identify and address potential infringement of their common law mark.

Trademark owners should ask one key question when deciding if another trademark or someone else's use of a mark is infringing: Is it likely to confuse consumers into thinking the products or services are connected to or endorsed by the trademark owner? The answer is obviously more complex and beyond the scope of this post, but common law trademark owners need to be proactive in protecting their rights against such infringing usage. 

One of the first and most important steps is monitoring the marketplace and trademark filings to identify potentially infringing marks. 

Monitor Trademark Usage

The U.S. Patent & Trademark Office (USPTO) publishes a weekly Official Trademark Gazette, which provides a list of pending trademark applications, as well as a searchable database of trademark applications and registrations where trademark owners can look for potentially conflicting marks. 

Owners must also be aware of other common law marks that are neither registered nor seeking registration, so conducting general searches within the marketplace for similar and unregistered marks is also important. 

However, when the 'marketplace' is essentially the entire internet, regularly searching for conflicting marks is obviously not a feasible option. There are many vendors that specialize in trademark watch services, or a more budget-conscious option would be to set up Google™ Alerts or conduct periodic Google™ searches to look for usage of marks that are confusingly similar to the owner's mark, or improper usage of the owner's own mark. This is a more basic level of monitoring, and so can be less effective, particularly when a mark consists of a common or widely used term. Although there is not one perfect fit for a trademark monitoring system, consistency of any search is the key to being able to react quickly when a potentially infringing use is identified.

Enforce Trademark Rights

When an owner identifies a potentially infringing mark, there is a range of enforcement mechanisms available to protect a common law trademark holder's rights in their marks, depending on the nature and severity of the infringement. Common enforcement options include:

• Cease and Desist Letter: This serves as a formal demand to stop the unauthorized use of a mark or to stop the use of another mark that is confusingly similar to a mark. This is often, but not always, a precursor to additional enforcement actions via the more formal methods outlined below:
• USPTO Opposition or Cancellation Proceeding: This is a way for members of the public, including common law trademark owners, to challenge a pending trademark registration (by filing an opposition to its registration) or for an existing registration, to file a petition for cancellation, on the grounds that the registration is damaging to their own trademark rights. If successful, it impacts only the registration of that conflicting mark, but not always the other owner's continued use of it.
• State or Federal Court Action: Owners of common law trademarks can bring an infringement action in federal court under Section 43(a) of the Lanham Act, or under state law in certain states, for false designation of origin or unfair competition. Enforcing a common law mark in federal court could be challenging, particularly if the USPTO has denied its registration because it failed to function as a mark. Such a USPTO finding would serve as persuasive evidence, potentially undermining the likelihood of success in any enforcement action.
• Social Media Usage Enforcement: In situations where unauthorized use is occurring primarily on social media platforms, trademark owners may be able to report infringing content or accounts in a takedown request through the platform's designated reporting system. The specific requirements and procedures for submitting such a request tend to vary by platform, and some may require proof of a federal trademark registration. 

In sum, any enforcement decisions should be made on a case-by-case basis and must take into account the mark's overall value to the owner's brand, the potential commercial significance of the infringing use, and, of course, the cost-effectiveness of the different options available. 

Even in the absence of federal registration for a mark, the owner can establish and maintain enforceable rights through consistent and bona fide use of a mark in commerce, coupled with proactive enforcement efforts and careful documentation. These practices can significantly enhance the strength and protectability of a mark under common law principles and increase the likelihood of a successful legal outcome should enforcement become necessary.