In the case of United States v. Mason, Administrator, et al., 1972, the Supreme Court ruled on a dispute involving federal estate tax law. The decedent had created an irrevocable trust for his wife and children during his lifetime but retained some control over it by reserving the right to change beneficiaries among a limited class of people (his descendants). After he died, the IRS included this trust in his taxable estate under Section 2036(a)(2) of Internal Revenue Code because they argued that he kept "strings attached" to these assets even after transferring them into an irrevocable trust. However, the executor of his estate disagreed with this interpretation and sued for a refund. The Supreme Court sided with the executor and held that retaining such power does not necessarily mean those assets should be included in one's gross estate for tax purposes unless there is evidence showing that such power was used or could have been used in conjunction with others to shift benefits among parties involved. This decision clarified how certain aspects of federal taxation laws apply when dealing with trusts where grantors retain some level of control.

In the dissenting opinion for United States v. Mason, Administrator, et al., Justice Douglas argued that the majority's decision to allow a tax deduction for theft losses suffered by a decedent prior to death was inconsistent with previous interpretations of relevant tax law. He contended that such deductions should only be permitted if they are related to property included in the gross estate and thus subject to taxation upon death. In this case, since the stolen assets were not part of the taxable estate at time of death due to their earlier theft, he believed there should be no corresponding deduction allowed against other assets in calculating estate taxes owed. Furthermore, Justice Douglas expressed concern about potential abuse and manipulation if such deductions were broadly permitted without clear legislative guidance or limitations.