Brazilian lawyer who hid AI instructions in court filings to try to win a case is fined by court
In Brazil, lawyers hid AI commands in a court document to win a case — they were fined
Brazil's Superior Court of Justice fined a lawyer 20,000 reais for hiding AI instructions in court filings, finding the conduct constituted procedural malice and undermined judicial authority. While reviewing a special appeal, the court found hidden text in multiple places on the page, one of which was printed on a decorative strip the same color as the background and illegible to the naked eye; after extraction, experts confirmed the content contained instructions directing an AI system to reach a conclusion favorable to the appellant, and included imperative phrases such as "write" and "strengthen" that are uncommon in ordinary pleadings. Presiding judge Paulo Sergio Domingues emphasized that the key issue was not whether the instructions bypassed the multi-layer protections of the STJ Logos AI system, but the means of hiding instructions in litigation documents itself; in this case the hidden instructions did not actually affect the outcome, and the special appeal was ultimately not accepted. The court also ordered a technical report and notified the Brazilian Bar Association and the Federal Public Ministry; the lawyer involved said the hidden fragments were remnants from using AI tools to draft the document.
A Brazilian court found a lawyer's hiding of prompts to be procedural bad faith and imposed a fine, showing that penalties may apply even when an injection does not succeed, which is a reference for institutions deploying judicial AI.