1. Kevin Mitnick
The most wanted computer criminal in United States history
First hacking start by exploiting the Los Angeles bus punch card system and getting free rides
Then hacking into the Digital Equipment Corporation's computer network and stealing software He has stated that he hacked into computers, scrambled phone networks, stole corporate secrets and hacked into the national defense warning system.
His fall came when he hacked into fellow computer expert and hacker Tsutomu Shimomura's home computer.
Now he is a computer security author, consultant and speaker
2. Adrian Lamo
Lamo's hit major organizations hard, hacking into Microsoft and The New York Times
He used Internet connections at coffee shops, Kinko's and libraries to achieve his feats earning him the nickname "The Homeless Hacker"
His target also include Yahoo!, Citigroup, Bank of America and Cingular.
Lamo's intrusion into The New York Times intranet placed him squarely into the eyes of the top cyber crime offenders and lastly he was caught.
Now he is a notable public speaker and award winning journalist.
3. Jonathan James
First time sent to prison for hacking when he was 16 years old.
He hit high profile organizations including the Defense Threat Reduction Agency, which is an agency of the Department of the Defense. With this hack he was able to capture usernames and passwords and view highly confidential emails.
James also hacked in NASA computers and stole software valued at over $1.7 million.
Upon discovering this hack, NASA had to shut down its entire computer system costing taxpayers $41,000
Today he own computer security company.
Hacker is Someone who has specific expertise in programming language and use his or her skills to compromise with the machine to gain something illegally (Andrik McVean, 2008)