The roots of 'cyberpunk' are early 1980s science fiction short stories. Gritty, urban, futuristic, dystopian. The idea is that technology won't liberate us, it'll just make everything faster, cheaper, dirtier, and more out of control.
The movement spawned a lot of bad music (Billy Idol) and bad films (Johnny Mnemonic).
The original stories, however, were excellent.
Wiliam Gibson, Burning Chrome
Mirrorshades: a cyberpunk anthology
Bruce Sterling, Schismatrix Plus
The Matrix films are just the Old Testament in cyberpunk style with Keanu playing Jesus.
'Cyberpunk' fashion is completely pose(u)r. Actual computer hackers wear obscure technology logo T-shirts that they got free at trade shows. Actual machine hackers wear cheap heavy work pants and T-shirts.