In the case of Cooter & Gell v. Hartmarx Corporation, et al., 1989, the U.S. Supreme Court addressed whether a district court could impose sanctions under Rule 11 of Federal Rules of Civil Procedure after a voluntary dismissal by plaintiffs and if it had jurisdiction to do so. The law firm Cooter & Gell filed an antitrust suit on behalf of their clients against Hartmarx Corporation but later voluntarily dismissed the claim when they realized that there was no factual basis for it. However, Hartmarx sought sanctions against them under Rule 11 which requires attorneys to certify that pleadings are well-grounded in fact and warranted by existing law or good faith argument for its extension. The District Court imposed monetary penalties on both the firm and one partner individually; this decision was upheld by Appeals Court as well. However, upon reaching Supreme Court review, it held that while courts can indeed assess Rule 11 sanctions even after voluntary dismissal because such dismissals leave standing previous filings (which may have violated rule), in this particular instance - since lower courts did not adequately explain why they found violations - case needed remand for further proceedings.

In the dissenting opinion for Cooter & Gell v. Hartmarx Corporation, it was argued that the majority's decision to allow appellate review of a district court's imposition of sanctions under Rule 11 contradicts precedent and undermines the rule’s purpose. The dissent pointed out that previous cases have established that such decisions are typically left to the discretion of trial courts due to their superior position in assessing factual circumstances. It was also noted that allowing appeals could potentially encourage frivolous litigation, as parties may be more likely to appeal sanctions if they believe there is a chance an appellate court will overturn them. This would not only waste judicial resources but also undermine Rule 11’s goal of deterring unnecessary filings and abusive litigation practices.