The prefix came to signify all things Net-related, and is now dying from overexposure. Most recent usage stems from the word "cyberspace" in William Gibson's Neuromancer, written in 1984. That word came from "cybernetics" (which itself spawned more jargon words in the 1960s...cyborg being just one), which means the science of control and communication (Norman Weiner, 1948). Cybernetics has its roots in kybernan a German verb meaning to steer or govern.