The illegal use of a trademark or service mark (or a substantially similar mark) on competitive or related products and services is referred to as trademark infringement. The effectiveness of a lawsuit to prohibit infringement is determined by whether the defendant’s usage generates confusion in the ordinary customer.
When a trademark owner (the plaintiff) discovers infringement, he or she may bring a lawsuit against the infringing user of the same or similar mark (the defendant) to prohibit further use of the mark and to recover monetary damages for the improper use.
In most cases, the success of an infringement depends on whether the defendant’s usage creates a probability of misunderstanding and so reduces the value of the plaintiff’s mark. To infringe on the rights of the owner, a mark does not have to be identical to one currently in use. If the proposed mark is similar enough to the previous mark to cause the ordinary consumer to be confused, its use may constitute infringement if the services or goods on which the two marks are used are linked to one another.