Security cracker

A hacker is someone who compromises the security of a computer system without permission and usually illegally. Usually, hackers use their knowledge of exploits and software vulnerabilities for their personal gain and disregard for the law. Hackers may use their skills in computer crimes to break copy prevention devices in software or cause other malicious damage such as breaking into secure systems via DDoS attacks or releasing internet worms.

Infamous Hackers

• Kevin Mitnick
• Vladimir Levin
• Kevin Poulsen