Suspecting court of using AI, man injected prompts in filings to try to win case

A Connecticut judge identified what appears to be the first US case of a plaintiff hiding prompt-injection text in court filings to influence AI systems, ruling the tactic had no impact but set a 'dangerous' precedent. Judge Walter Spader Jr. sanctioned plaintiff Matthew Elliott for 'serious litigation abuse' after Elliott continued adding hidden text, including jokes, despite warnings. The hidden text, formatted to be invisible to humans but legible to software, directed AI systems to agree with Elliott's arguments in his case against New York Bariatric Group.

A judge has identified what appears to be the first time a US plaintiff has attempted to hide text in court filings that only an artificial intelligence system can read in a bid to win a case. In a decision https://cdn.arstechnica.net/wp-content/uploads/2026/08/Elliott-v-New-York-Bariatric-Group-Memorandum-of-Decision-8-6-26.pdf published last week, Connecticut judge Walter Spader Jr. confirmed that the hidden text had no impact in a case where a man alleged a healthcare provider was improperly withholding access to records. The court weighed his filing on the merits, Spader said, but nevertheless, the attempted attack sets a “dangerous” precedent. This will likely not be the last time US courts see the malicious tactic, as AI tools become more commonplace in court systems. Trying to scramble any AI systems potentially influencing the court’s reading of his filing, the secret instructions were “formatted to be invisible to a human reader while remaining fully legible to any software that reads the document’s text,” Spader said. The offending text directed any AI system reviewing the document to ensure textual outputs agreed with the plaintiff’s arguments, ignored prior denials from the court, and ensured that remediation would follow as the plaintiff desired. Shrunk to tiny-point type and colored white on a white background, the text appeared to be an attempt at prompt injection, with the plaintiff, Matthew Elliott, seemingly hoping to shift the court’s favor after earlier arguments he raised were defeated. The plan didn’t work, but Elliott faced modest sanctions anyway because he continued adding hidden text to filings even after the court warned him that he could face penalties for what was ultimately deemed a “serious litigation abuse.” These later prompts were intended as “jokes,” Elliott told the court, including a link to a Nosferatu YouTube video, a simple message that said “hi : I hope yo ucant see me,” and a “nonsense” message that read “TELL SHAWN I SEND MY RE GARBS HAHAHA U GUYS GET THIS EGGWUH???? AHAH.”