George Duke-Cohan, 19, made a threat from his bedroom against a United Airlines flight from the UK to San Francisco. He called San Francisco airport and claimed to be a father whose daughter had called him from the flight to say that the flight had been hijacked and one of the hijackers had a bomb. Duke-Cohan was under police investigation at the time for sending a mass email to thousands of schools telling them there were pipe bombs on their premises, causing around 400 institutions to evacuate.