Brazilian Courts Fine Lawyers for Misusing AI in Legal Filings

A judge of the 9ª Câmara Cível of the Paraná state court fined lawyer Giovanni Antônio de Luca R$ 20 million (2% of a claimed R$ 1 billion case) for citing a non‑existent precedent that appeared to be generated by artificial intelligence. The court deemed the act "litigância de má‑fé" and ordered the state bar association to investigate the lawyer’s conduct.

In a separate case, the Tribunal de Justiça da Paraíba imposed a total fine of R$ 32,800 on another attorney after identifying hidden AI prompts in a petition. The judge described the practice as "Invisible Prompt Injection" and referred the matter to the local bar association and the public prosecutor for possible disciplinary action. Both rulings underscore Brazilian courts' increasing scrutiny of AI tools used in legal arguments.