In the case of Village of Willowbrook v. Grace Olech, 1999, the U.S Supreme Court ruled in favor of Grace Olech, a resident who sued her village for discrimination under the Equal Protection Clause. The dispute began when Ms. Olech requested a water connection from her local municipality after her well became contaminated; however, she was told that she would have to grant an easement five times larger than what other residents were required to give up. She agreed but later filed suit claiming that this demand constituted "class-of-one" discrimination - treating one person differently from others similarly situated without any rational basis for doing so. The court held that such claims are valid under the Fourteenth Amendment's Equal Protection Clause and set precedent by broadening its interpretation beyond protecting classes or groups against discriminatory laws and actions to include individuals as well.

In the dissenting opinion for Village of Willowbrook v. Olech, Justice Breyer argued that the majority's decision to recognize a "class of one" equal protection claim was too broad and could potentially open up floodgates to numerous lawsuits based on subjective perceptions of unfair treatment. He expressed concern about courts being inundated with claims from individuals who believe they have been treated differently than others in similar situations, even when there is no evidence of discriminatory intent or purpose. Instead, he suggested that such claims should be limited to cases where there is clear proof that differential treatment has occurred due to personal animosity or ill-will rather than legitimate government interests.