The U.S. Supreme Court case Harris Trust and Savings Bank v. Salomon Smith Barney Inc., in 1999, revolved around the interpretation of provisions under the Employee Retirement Income Security Act (ERISA). The dispute arose when a pension plan sold securities to an entity that was not qualified as per ERISA guidelines, leading to losses for the plan participants. The question before the court was whether or not parties involved in such transactions could be held liable even if they were unaware of their non-compliance with ERISA rules at the time of transaction. In its decision, the Supreme Court ruled that any party engaging in prohibited transactions can indeed be held accountable regardless of their knowledge about potential violations at that time. This ruling reinforced stricter adherence to ERISA regulations by all entities dealing with employee benefit plans.

In the dissenting opinion for Harris Trust and Savings Bank v. Salomon Smith Barney Inc., Justice Scalia argued that the majority had misinterpreted section 502(a)(3) of ERISA (Employee Retirement Income Security Act). He contended that this provision does not allow a fiduciary to sue another party for equitable relief unless they have violated their duties under ERISA, which was not proven in this case. The majority's interpretation, he claimed, would effectively make any transaction involving plan assets subject to suit if it could be shown that some benefit accrued to a party who knew or should have known of the existence of an ERISA plan. This broad reading would create uncertainty and potential liability far beyond what Congress intended when it enacted ERISA.