Kevin Mitnick is a computer security consultant, author, and reformed hacker. He gained notoriety in the 1990s as one of the most wanted computer criminals in the United States. He was arrested in 1995 and later convicted of various computer-related crimes, including unauthorized access to computer systems and wire fraud.

Mitnick's hacking career began in the 1970s when he was still in high school. He was fascinated with the inner workings of telephone systems and began experimenting with ways to manipulate them. He eventually discovered that he could use social engineering techniques to trick telephone company employees into giving him access to the company's systems. He would then use this access to make long-distance phone calls for free. This is known as "phreaking."

In the 1980s, Mitnick began to focus on hacking into computer systems. He was able to gain access to a number of high-profile computer systems, including those belonging to the Los Angeles Police Department, the Department of Defense, and the Pentagon. He was also able to steal software and other proprietary information from a number of major corporations, including Motorola and Sun Microsystems.

In 1992, Mitnick was arrested and charged with several computer-related crimes. He was released on bail, but later violated the terms of his release by continuing to hack into computer systems. This led to a nationwide manhunt for Mitnick, which finally ended in his arrest in 1995.

After his arrest, Mitnick was held in a federal prison for several years, during which time he was denied access to computers and the internet. He was finally released in 2000 and has since become a reformed hacker, using his knowledge and experience to help organizations improve their computer security.

Mitnick has also become a well-known author and speaker on the topic of computer security. He has written several books on the subject, including "The Art of Intrusion: The Real Stories Behind the Exploits of Hackers, Intruders and Deceivers" and "The Art of Deception: Controlling the Human Element of Security." He is also a regular speaker at security conferences and other events.

To review, Kevin Mitnick is a reformed hacker and computer security consultant who gained notoriety in the 1990s for his involvement in a number of high-profile computer-related crimes. He was arrested in 1995 and later convicted of various computer-related crimes, including unauthorized access to computer systems and wire fraud. Since his release from prison in 2000, he has become a respected author and speaker on the topic of computer security and is a well-known figure in the computer security industry.