In the 1949 case Hubsch v. United States, the Supreme Court dealt with issues surrounding tax evasion and conspiracy. The defendants, Mr. and Mrs. Hubsch, were charged with conspiring to defraud the U.S government by evading income taxes through a complex scheme involving multiple businesses they owned or controlled in Los Angeles between 1937-1946. They allegedly manipulated their business records to understate their taxable income significantly over this period. The defense argued that there was insufficient evidence of an agreement between them to commit fraud; however, the court ruled against this argument stating that such agreements could be inferred from circumstantial evidence like concerted actions towards a common goal. Furthermore, it was contended by defendants that certain statements made outside of court should not have been admitted as evidence because they were hearsay (statements made out-of-court presented for truth). However, these objections were also dismissed on grounds that those statements fell within exceptions to hearsay rules since they pertained directly to furtherance of alleged conspiracy. Ultimately, both Mr. and Mrs.Hubsch's convictions for tax evasion and conspiracy were upheld by Supreme Court.

In the dissenting opinion for Hubsch v. United States, it was argued that the majority's decision to uphold the conviction of a man accused of violating federal laws related to alcohol taxation and distribution was flawed. The main point of contention revolved around whether or not evidence obtained through wiretapping should be admissible in court. The dissenting justices believed that this constituted an unreasonable search and seizure, thus violating the Fourth Amendment rights of the defendant. They also expressed concern about potential abuses by law enforcement if such practices were allowed to continue unchecked, arguing that allowing illegally obtained evidence could lead to widespread violations of civil liberties under the guise of enforcing tax laws or other regulations. Furthermore, they disagreed with how lower courts had interpreted relevant statutes and felt these interpretations were overly broad in scope.