What was hallucinated

Fabricated: Case Law | Plaintiff cited dozens of cases the Court was unable to locate, including some falsely attributed to this Court; Court identified earlier inability to locate two such cases. || False Quotes: Case Law | Plaintiff attributed language to Richter v. CC-Palo Alto, Inc. and Carlson v. Coca-Cola Co. that does not appear in those opinions. || False Quotes: Legal Norm | Plaintiff quoted language purportedly from California Code of Civil Procedure § 356 that bears no similarity to the actual statute. || Fabricated: Case Law | Plaintiff's opposition to the fee motion cited authorities that were entirely fabricated or did not support the propositions for which they were cited.

Details

The Court found plaintiff repeatedly cited cases that could not be located and attributed false quotations to existing cases and statutes, concluding many citations were AI-generated; awarded reduced fees under §1927 given pro se status.

Sanction teardown · C.D. California, USA · 2025-12-23

Minjie Zheng v. ICANN

What happened

In C.D. California, USA, a filing relied on an unnamed/unconfirmed AI tool to help draft legal argument. The court identified the following problems with the citations in that filing:

Fabricated (Case Law)

Plaintiff cited dozens of cases the Court was unable to locate, including some falsely attributed to this Court; Court identified earlier inability to locate two such cases.
False Quotes (Case Law)

Plaintiff attributed language to Richter v. CC-Palo Alto, Inc. and Carlson v. Coca-Cola Co. that does not appear in those opinions.
False Quotes (Legal Norm)

Plaintiff quoted language purportedly from California Code of Civil Procedure § 356 that bears no similarity to the actual statute.
Fabricated (Case Law)

Plaintiff's opposition to the fee motion cited authorities that were entirely fabricated or did not support the propositions for which they were cited.

Which AI tool

an unnamed/unconfirmed AI tool. Note: Charlotin's public database records tool attribution only where a court order, brief, or reporting on the matter states it explicitly; "unidentified" or "implied" means the record indicates AI use but does not name a specific product — we do not guess.

Outcome

Monetary Sanction (monetary penalty: 66129 USD.)

Additional detail

The Court found plaintiff repeatedly cited cases that could not be located and attributed false quotations to existing cases and statutes, concluding many citations were AI-generated; awarded reduced fees under §1927 given pro se status.

How Citation Safe would have caught this

Citation Safe runs three deterministic layers before a brief is filed: (1) does the citation exist against CourtListener's database of published opinions, (2) if quoted, does that exact language appear in the source, (3) does the cited case actually support the proposition it is cited for. Fabricated case citations fail Layer 1. Fabricated or misattributed quotations fail Layer 2 even when the underlying case is real. Misrepresented holdings — a real case cited for a proposition it does not support — are the target of Layer 3. None of these checks involve asking another language model whether the citation looks right; they are lookups and text-matches against the actual source, which is why a hallucinated citation has to survive a direct lookup against the authoritative source — not another model's opinion — to earn a VERIFIED stamp; our measured false-verify rate is published live at /quality.

Check a brief before you file it → · See our live false-verify rate

Source: https://www.damiencharlotin.com/documents/1329/Zheng_v._ICANN_USA_23_December_2025.pdf, via Damien Charlotin's public AI Hallucination Cases Database (CC0).