A Connecticut judge has sanctioned a plaintiff after he hid prompt-injection text in court filings, apparently hoping to influence any artificial intelligence system used to read or assess them. Judge Walter Spader Jr. said the tactic did not affect the case’s outcome, as the Connecticut Judicial Branch does not use AI to review or decide filings, but warned that it could set a dangerous precedent as AI becomes more common in courts.

Matthew Elliott used tiny white text on a white background to instruct any AI reader to support his arguments, disregard earlier court denials and grant his preferred remedy in a dispute over healthcare records. After being warned, he continued inserting hidden messages that he described as jokes; the judge found this “serious litigation abuse”, imposed modest sanctions and rejected Elliott’s claim that he was merely auditing suspected court AI use.