Cassandra will always be with us. I don't mean whiners pining for a simpler time, halcyon days, community, blah blah blah. No, I mean voices warning of future dangers visible to anyone with the foresight, intelligence and time to follow a thought to its logical conclusion.
Almost two centuries ago, Mary Wollstonecraft Shelley ruminated on man's hubris and the opportunities afforded by science and produced a humdinger of a novel. It has danced through our collective imagination ever since, offering a ready label for anything that seemed to overstep the proper bounds of human activity. "Frankenstein" yielded a few sleepless nights, some great flicks (and a few dogs), but didn't much shape human behavior, judging from the stream of animals being cloned these days.
About the last person to take her warnings seriously is doing life-plus in a maximum-security lockup in the United States. Say what you will about Ted Kaczynski, a k a the Unabomber -- and make sure "murderer" and "criminally insane" are somewhere in there -- but the logic that drove him is, sadly, not the product of a feverish imagination.