White Hat hackers are also known as Ethical Hackers. They never intent to harm to a system, rather they try to find out weaknesses in a computer or a network system
as a part of penetration testing and vulnerability assessments.
Ethical hacking is not illegal and it is one of the demanding jobs available in the IT industry. There are numerous companies that hire ethical hackers for penetration testing and vulnerability assessments.
Ethical Hackers are try to find out the weakness of a system. And help to remove the weakness. Mostly companies are pay a lot of money to Ethical Hacker because they are tell about the weakness of the system by which a company develop high secure system.