How to Stop Others From Using a Trademark
Typically, you begin by sending a letter, called a "cease and desist letter," to the wrongful ("infringing") user, demanding that it stop using the mark.
If the wrongful user continues to infringe the mark, you can file a lawsuit to stop the improper use. The lawsuit is usually filed in federal court if the mark is used in more than one state or country, and in state court if the dispute is between purely local marks.
In addition to preventing further use of the mark, you can sometimes obtain money damages from the wrongful user.
Damages for Trademark Infringement
If you can prove in federal court that the infringing use is likely to confuse consumers and that the business has suffered economically as a result of the infringement, the infringer may have to pay you money damages based on the loss.
If the court finds that the infringer intentionally copied your trademark, or at least should have known about the existing trademark, the infringer may have to give up the profits it made by using the mark as well as pay other damages, such as punitive damages, fines, or attorney fees.
On the other hand, if your business has not been damaged, a court has discretion to allow the other company to continue to use the trademark under limited circumstances that are designed to avoid consumer confusion.