In business, it is essential to protect your intellectual property. If someone infringes upon your intellectual property rights, you should take action to stop them.
Trademark infringement especially can be quite damaging to your business. The U.S. Patent and Trademark Office defines it as the unauthorized use of a trademark on goods or service that would cause consumer confusion. Note the mark in question does not have to be exactly the same but only require a high degree of similarity.
If someone uses your trademark and you did not give that person permission to do so, then you may have a claim. However, simply using someone else’s trademark is not enough to constitute infringement.
The important aspect is how the person uses your trademark. If he or she uses it on a good or service that is similar to yours, it could confuse customers. You need to show that by using your trademark, the person could trick or mislead customers into believing they are buying your product or service.
The use also requires that the person does it in a way where it is difficult for customers to know that the goods or services are not from you. The best example is a counterfeit good that looks exactly like your good.
In addition to showing the use would cause consumer confusion and that you did not provide permission for use, you will also have to show that you own the mark and your use of the mark takes priority. You need to be the first to use it or register it to claim priority.