Cyberpunk escaped from being a literary genre into cultural reality. People started calling themselves cyberpunks, or the media started calling people cyberpunks. The first people to identify themselves as cyberpunks were adolescent computer hackers who related to the street-hardened characters and the worlds created in the books of William Gibson, Bruce Sterling, John Shirley and others. Cyberpunk hit the front page of the New York Times when some young computer kids were arrested for cracking a government computer file. The Times called kids "cyberpunks". Finally, cyberpunk has come to be seen as a generic name for a much larger trend more or less describing anyone who relates to the cyberpunk vision. This, in turn, has created a purist reaction among the hard-core cyberpunks, who feel they got there first.
-- R.U. Sirius, Mondo 2000: A Users Guide to the New Edge
The word "cyberpunk" was originally a marketing term applied to Science Fiction writings of William Gibson and Douglas Rushkoff, but was soon taken up by many Internet users as a description of a lifestyle, culture or community to which they imagine they belong. So cyberpunk became the way of thinking and attitude for many people in the Net and in so called Real Life.
This is due to the fact that they correctly noticed the seeds of the fictional world of cyberpunk in Western society today. Our world is evolving into a typical "cyberpunk-world" : the rising amount of technology in our everyday lives - we thrive and survive on technology, the development of the cities into huge "sprawls", drugs and crime. All these aspects of our culture fit nicely into the world of cyberpunk - the future now.
So, the world from the works of Gibson and Blade Runner is becoming a stark reality.