In the United States v. Merchant case of 1986, the Supreme Court examined whether a defendant's Sixth Amendment right to confront witnesses against him was violated when his co-defendant's confession implicating both of them was introduced at their joint trial, but the co-defendant did not testify. The court held that such an introduction does violate the Confrontation Clause if it is done in a manner that allows jurors to consider it as evidence against both defendants and if there are no adequate limiting instructions provided by the judge. In this case, although limiting instructions were given, they were deemed insufficient because they did not explicitly instruct jurors to disregard any references made about Merchant in his co-defendant’s statement while considering charges against him.

In the dissenting opinion for United States v. Merchant, 1986, it was argued that the majority's interpretation of the law was too broad and could potentially infringe upon individual rights. The dissenting justices believed that while there is a need to protect society from potential harm caused by illegal activities such as drug trafficking, this should not come at the expense of violating an individual's constitutional rights. They expressed concern over how far-reaching this ruling could be in terms of its implications on privacy rights and due process protections under Fourth Amendment jurisprudence. Furthermore, they disagreed with the majority’s view about what constitutes reasonable suspicion or probable cause for search and seizure without a warrant in certain circumstances related to criminal investigations involving controlled substances. In their view, more stringent standards were necessary to prevent arbitrary enforcement actions by law enforcement authorities which might undermine civil liberties guaranteed under U.S Constitution.