The U.S. Supreme Court case Boeing Co. v. Van Gemert et al., 1979, revolved around a class action lawsuit brought against the Boeing Company by its shareholders who had not redeemed convertible debentures before their expiration date in 1966. The plaintiffs argued that they were not adequately notified about the expiry of these securities and thus lost out on potential profits when they were automatically converted into common stock at a lower value than market price. Boeing contended that it was under no obligation to notify holders of this automatic conversion as per the terms agreed upon during purchase, but both district and appellate courts ruled in favor of the plaintiffs. Upon reaching the Supreme Court, justices upheld previous rulings stating that Boeing was liable for damages because it held onto funds belonging to those shareholders who failed to redeem their debentures due to lack of notice from company's end regarding impending conversion deadline. This decision established an important precedent concerning corporate responsibility towards security holders and set guidelines for adequate notification procedures related to changes or actions affecting shareholder investments.

In the dissenting opinion for Boeing Co. v. Van Gemert, Justice Rehnquist disagreed with the majority's decision to award damages based on an estimated number of unclaimed shares rather than actual claims made by shareholders. He argued that this approach violated basic principles of due process and fairness because it allowed plaintiffs to recover more than they were actually entitled to under law. Furthermore, he contended that there was no legal basis for imposing a constructive trust on funds belonging to Boeing in favor of absent class members who had not come forward or proven their claims within the statute of limitations period. In his view, such a ruling could potentially lead companies into bankruptcy if applied broadly and indiscriminately across all class action lawsuits involving unclaimed property or securities.