Hacker : White hat and Black Hat

I thought it would be good to start with something simple and straight forward, so what is a hacker and what kind of hackers are out there.. 

In common usage, a hacker is a person who breaks into computers, but does no harm. usually for fun or just the challenge . The subculture that has evolved around hackers is often referred to as the computer underground but is now an open community. hackers are people who are motivated by curiosity and adventuress spirit.

Other uses of the word hacker exist that are not related to computer security (computer programmer and home computer hobbyists), but these are rarely used by the mainstream media because of the common stereotype that is in TV and movies. Some would argue that the people that are now considered hackers are not hackers, as before the media described the person who breaks into computers as a hacker there was a hacker community. This community was a community of people who had a large interest in computer programming, often sharing, without restrictions, the source code for the software they wrote. These people now refer to the cyber-criminal hackers as "crackers". 

White hat
A white hat hacker breaks security for non-malicious reasons, for instance testing their own security system. This type of hacker enjoys learning and working with computer systems, and consequently gains a deeper understanding of the subject. Such people normally go on to use their hacking skills in legitimate ways, such as becoming security consultants. The word 'hacker' originally included people like this, although a hacker may not be someone into security.

 Black Hat
 A black hat hacker, sometimes called "cracker", is someone who breaks computer security without authorization or uses technology (usually a computer, phone system or network) for vandalism, credit card fraud, identity theft, piracy, or other types of illegal activity.