US judge sanctions lawyers $12,000 over AI fabricated legal filings

A U.S. federal judge has fined a group of attorneys $12,000 for submitting court documents containing fictitious case citations and quotations generated by artificial intelligence, marking a significant judicial response to the misuse of AI in legal practice.

The sanctions were levied by U.S. District Judge Julie Robinson in Kansas against lawyers representing Lexos Media IP in a patent lawsuit against online retailer Overstock.com. Judge Robinson found the attorneys violated their professional duties by failing to verify AI-generated content before filing it with the court.

In her ruling, Judge Robinson emphasized that all lawyers who sign court filings bear responsibility for their accuracy, regardless of who used the AI tool. “A reasonably competent attorney filing documents in court should be aware of the pronounced, well-publicized risks of using unverified generative AI for legal research,” she stated.

The court discovered that several filings included “non-existent quotations and case citations”—a known AI error often called “hallucination.” This prompted the judge in December to order five attorneys on the case to show why they should not face penalties.

“The sheer amount of case law that has erupted over the last few years due to attorneys’ reliance on unverified generative AI research, often generating hallucinated legal authority, is staggering,” Judge Robinson noted, highlighting a growing challenge for the judiciary.

The largest fine, $5,000, was imposed on Sandeep Seth, who admitted to using ChatGPT without checking its output, citing personal pressures. He has been ordered to provide a copy of the ruling to state disciplinary authorities and outline his firm’s new safeguards. In an email, Seth called the incident “an embarrassing lesson,” adding that firms must implement “strict policies” to avoid such errors.

Attorneys Kenneth Kula and Christopher Joe were each fined $3,000 for not reviewing documents they signed, while local counsel David Cooper was fined $1,000 for failing to check citations. The lawyers representing Overstock.com declined to comment.

The case, Lexos Media IP LLC v. Overstock.com Inc, continues in the U.S. District Court for the District of Kansas. It joins a series of recent rulings nationwide reminding legal professionals that AI does not absolve them of their ethical duty to ensure the accuracy of court submissions.