In the case of Lamont v. Postmaster General (1964), the United States Supreme Court ruled in favor of Corliss Lamont, a publisher who was challenging a provision of the Postal Service and Federal Employees Salary Act of 1962. The law required that recipients of "communist political propaganda" through international mail had to specifically request delivery from their local post office; otherwise, it would be withheld by postal authorities. Lamont argued this violated his First Amendment rights to receive information freely without government interference or surveillance. The Supreme Court unanimously agreed with him, stating that freedom to communicate includes both sending and receiving information and ideas - even if they are unorthodox or unpopular - without any governmental intervention.

In the dissenting opinion for Lamont v. Postmaster General, Justice Harlan argued that the majority's decision to strike down Section 305(a) of the Postal Service and Federal Employees Salary Act was a misinterpretation of Congress' intent. He believed that this provision did not infringe upon First Amendment rights but rather sought to protect citizens from unwanted mailings containing communist propaganda. According to him, it was an opt-in system where recipients could choose whether or not they wanted such materials delivered by notifying their local post office. Furthermore, he contended that if any part of Section 305(a) were unconstitutional, it would be more appropriate for the Court to nullify only those parts while leaving intact its other provisions - a process known as "severability". Lastly, Justice Harlan expressed concern over potential implications on future legislation aimed at regulating postal services in light of national security concerns.