11 Court Opinions in the Last 30 Days Mention AI-Hallucinated Material, and …

that's likely just the tip of the iceberg.

I did a Westlaw search, and found that 11 court opinions in the last 30 days mention that a party had likely included AI-hallucinated case citations or (in one instance) AI-hallucinated quotes from real cases; ten involved court filings, and one involved a party's communication with opponents. That's a rate of over 100 per year.

And that's likely just the tip of the iceberg, since the overwhelming majority of all court cases in the U.S. are state trial court cases, and opinions in those cases only rarely make it onto Westlaw. Eight of the cases I found were federal trial court cases, two were state appellate cases, and one was a state trial court case. This makes me think there are many more state trial court cases in which such hallucinations were noticed and mentioned but which aren't on Westlaw, and still more in which such hallucinations weren't mentioned or weren't even noticed.

Six of the cases involved pro se litigants, but five involved lawyers.