It goes without saying that we live in panicked times. But what's less obvious is that panic has a logic. Much like the Three Laws of Robotics, panic has rules, and they are:
Panic Rule #1: If it happened before, it'll happen again.
Panic Rule #2: It has to happen to someone.
Panic Rule #3: Just because it hasn't happened doesn't mean it won't.
Take Panic Rule #1. If there was a cataclysmic event that made the dinosaurs extinct in the past, what's keeping it from happening again? As for #2, don't let anyone tell you that the odds of your plane crashing are extraordinarily low--it has to happen to someone, and that someone is you. Just because the sun hasn't gone supernova yet doesn't mean it won't happen tomorrow (#3).
Those kind of attitudes of complacent safety anger the panic gods and cause them to wreak vengeance by sending plague after plague upon the populace: locusts; SARS; stars and their obsession with Kabbalah. It's too risky not to worry, at least a little; and worry we will accomplish here, on a regular basis and with zeal.