AI tools like Claude, Chat GPT, and others are being misused to create fictitious cases and citations in legal filings in Oregon and other parts of the United States. Photo taken on April 28, 2026.
Alison Frost / OPB
Oregon’s high court on Friday dismissed parts of two lawsuits that used fabricated AI-generated citations, marking the first time the state’s highest court has addressed false information from artificial intelligence.
Experts across the country are warning that lawyers and individuals representing them in court are increasingly using AI products that fabricate false citations and citations. Researchers estimate that AI tools are responsible for inaccuracies in more than 1,000 cases.
Some of those cases have made national headlines. Last summer, lawyers representing the CEO of bedding maker MyPillow were each fined $3,000 in federal court for using AI to submit dozens of incorrect applications. In Oregon, a lawyer was fined $110,000 in district court, making it the largest fine ever.
But this is the first time the Oregon Supreme Court has addressed the issue.
“We recognize that AI products may seem like an attractive shortcut to legal research and presentation of legal arguments,” Oregon Supreme Court Chief Justice Megan A. Flynn said in a statement Friday about the ruling. “But if courts have to spend significant time and effort addressing fabricated legal arguments, other cases will be sacrificed.”
Related: Unethical use of AI in legal proceedings is on the rise in Oregon and the US, with penalties
In the first case the court heard, the justices denied a mandamus petition. Plaintiffs in this case used LegalAI to submit exhibits containing false citations, citing non-existent past cases. When asked to resubmit the document, it still contained AI-generated falsehoods.
“However, rather than take the time necessary to avoid increasing the court’s burden,” the plaintiffs dug an even deeper hole less than 12 hours after receiving the order, filing a “declaration containing citations to at least four cases not present in the Oregon Appellate Report or the Oregon Report,” the judges wrote in their order.
In another case, the defendant filed documents citing legal arguments that could not be tested under Oregon case law. The high court fined the defendants $500 and allowed them to resubmit the documents.
Anchor Doshi, general counsel for the Oregon State Bar, told OPB’s “Think Out Loud” in April that AI fabrications have also been found in documents submitted by attorneys and individuals they represent in court. In many cases, the person in question doesn’t know that AI is generating a fake case, so it takes time and resources for courts to figure out what happened.
“That’s one of the main factors that makes this case so bad,” Doshi said. “Because these citations are fabricated, they must be retrospectively reviewed by the court, creating additional work. But in addition to that, they also create additional work for opposing counsel, which can result in higher attorney fees for the opposing side.”
