Defending American Courts Act This bill imposes limitations relating to a person (i.e., individual or entity) that seeks to use an injunction from a foreign tribunal to restrict a patent infringement claim in the United States. For example, if the person asserting such a foreign injunction has been found liable for patent infringement in a U.S. court, that court shall, with certain exceptions, make specified presumptions that generally increase the likelihood of the court (1) increasing the damages awarded in the case, and (2) awarding attorney fees to the patent owner.