Families of Canadian Mass Shooting Victims Sue OpenAI and Sam Altman in U.S. Court

On April 29, 2026, seven lawsuits were filed in a California court by families of victims of a mass shooting in Canada. The lawsuits accuse OpenAI and its CEO, Sam Altman, of negligence and abetting the attack by failing to flag the suspect's use of ChatGPT. The cases claim that OpenAI's systems should have detected and reported the suspect's harmful behavior. The lawsuits specifically target OpenAI's responsibility in allowing the suspect to access and use ChatGPT without proper monitoring or intervention. The legal action follows a mass shooting in Canada, where the suspect is alleged to have used AI-generated content to plan the attack. The cases are being pursued in a U.S. court, raising questions about jurisdiction and the legal accountability of AI companies.