Nobody could find the decisions or the quotations cited and summarised in the brief because ChatGPT had invented everything. Photograph: Gabby Jones/Bloomberg The legal action began like so many others: A man named Roberto Mata sued the airline Avianca, saying he was injured when a metal serving cart struck his knee during a flight to Kennedy International Airport in New York. When Avianca asked a Manhattan federal judge to toss out the case, Mr Mata’s lawyers vehemently objected, submitting a 10-page brief that cited more than a half-dozen relevant court decisions. There was Martinez v Delta Air Lines, Zicherman v...