Kevin Mitnick
Kevin David Mitnick is a computer security consultant and author. He was a world-famous controversial computer hacker in the late 20th century, who was, at the time of his arrest, the most wanted computer criminal in United States history.”.



Linus Torvalds
A true hacker in the classic sense, Linus Torvalds was a computer science student at the University of Helsinki when he wrote the operating system Linux (a contraction of "Linus' Minix") in 1991. He's humble, he's brilliant, he gave us all access to Unix.

What Is Black Hat Hacker
A black hat hacker, also known as a cracker or a dark side hacker (this last definition is a direct reference to the Star Wars movies and the dark side of the force), is someone who uses his skills with a criminal intent. Some examples are: cracking bank accounts in order to make transferences to their own accounts, stealing information to be sold in the black market, or attacking the computer network of an organization for money.
Some famous cases of black hat hacking include Kevin Mitnick, who used his black hat hackers skills to enter the computers of organizations such as Nokia, Fujitsu, Motorola and Sun Microsystems (it must be mentioned that he is now a white hat hacker); Kevin Poulsen, who took control of all the phone lines in Los Angeles in order to win a radio contest (the prize was a Porsche 944 S2); and Vladimir Levin, which is the handle of the mastermind behind the stealing of $10'000,000 to Citigroup.
Differences Between White Hat And A Black Hat Hacker
The difference between black hat and white hat hackers is that white hat hacker uses their skills and knowledge as a way to defend someone from attackers. That means that white hat hackers offer their services to corporations, public organizations and educational institutions.
These services include a complete revision of their computer network security, implementation of new security systems (they may be hardware or software), user training and future recommendations. All these measures will be able to combat unauthorized hacking; black hat hackers, however, will continue trying.
Black hat SEO tactics such as spamdexing, attempt to redirect search results to particular target pages in a fashion that is against the search engines' terms of service, whereas white hat methods are generally approved by the search engines. White hats tend to produce results that last a long time, whereas black hats anticipate that their sites may eventually be banned either temporarily or permanently once the search engines discover what they are doing.