In Jaben v. United States (1964), the U.S. Supreme Court ruled on a case involving an individual who was charged with willfully failing to supply information for his income tax return, which he claimed violated his Fifth Amendment right against self-incrimination. The defendant, Louis Jaben, had filled out all parts of his tax form except for the sections requiring financial details and instead attached a statement asserting that providing such information could potentially incriminate him in violation of state or federal law. The court held that simply because there is potential risk involved does not mean one can refuse to provide any information at all; rather it must be demonstrated how answering specific questions would likely lead to self-incrimination. Therefore, the court affirmed Jaben's conviction as he failed to show how supplying this particular data would have implicated him in illegal activities.

In the dissenting opinion for Jaben v. United States, Justice Harlan argued that the majority's decision to reverse and remand was incorrect because it failed to consider whether or not there was a reasonable cause for the IRS summons in question. He believed that this failure undermined the purpose of such summonses, which is to aid in determining tax liability. Furthermore, he disagreed with their interpretation of Section 7605(b) as requiring an initial determination by a court before any second inspection can occur; instead, he viewed it as merely providing taxpayers with protection against unnecessary examinations. He also criticized their reliance on dicta from Reisman v. Caplin and suggested they were overstepping judicial boundaries by imposing requirements not specified by Congress.