In Ingram et al. v. United States, the Supreme Court ruled in 1958 that a group of taxpayers who had received income from illegal gambling activities were required to pay taxes on those earnings under the Internal Revenue Code. The defendants argued that requiring them to report their illegal income violated their Fifth Amendment right against self-incrimination, but the court disagreed and upheld their convictions for tax evasion. The court reasoned that while individuals cannot be compelled to disclose information which may incriminate them, they are still obligated by law to report all taxable income - whether it was legally or illegally obtained - and pay appropriate taxes on it.

In the dissenting opinion for Ingram et al. v. United States, Justice Brennan disagreed with the majority's interpretation of Section 2(b) of the Clayton Act as it pertains to price discrimination and its effects on competition. He argued that a buyer could only be held liable if they knowingly induced or received discriminatory pricing that would harm competition, not simply because they passively accepted lower prices from sellers looking to gain an advantage over their competitors. In his view, this interpretation was more consistent with Congress' intent when drafting the legislation - namely, to protect consumers by promoting fair and open competition in markets across America. Furthermore, he expressed concern about how this ruling might discourage buyers from negotiating better deals out of fear they may inadvertently violate antitrust laws.