NEW YORKHaving devoted cover stories to the threats of Hepatitis C, identity theft, and airport security, the editors of Newsweek spent Monday arguing over what they should stoke fears of next. 'We could do the dangers of caffeinethat'd get people pretty worked up,' managing editor Jon Meacham said. 'Or how about daycare workers? There must be some alarming new study revealing just how few of them undergo background checks.' Among the other ideas the editors proposed: the possible link between laptop computers and stomach cancer, the potential threat of water-supply poisoning by terrorists, and stunning new Biblical evidence pointing to April 4, 2004, as the date of the apocalypse. 