White Hat Hacking

Hacking as a subject is really interesting but in most cases it's highly illegal, there are ways around it though, such as being a white hat hacker.

From the wikipedia article called "White hat":

"White hat hackers, also known as "ethical hackers," are computer security experts, who specialize in penetration testing, and other testing methodologies, to ensure that a company's information systems are secure. Such people are employed by companies where these professionals are sometimes called "sneakers." Groups of these people are often called tiger teams or red teams. These security experts may utilize a variety of methods to carry out their tests, including social engineering tactics, use of hacking tools, and attempts to evade security to gain entry into secured areas.

The National Security Agency offers certifications such as the CNSS 4011. Such a certification covers orderly, ethical hacking techniques and team management. Aggressor teams are called "red" teams. Defender teams are called "blue" teams."

To even become a real hacker you have to consume endless amount of information about operating systems and various other things, naturally what you need to learn depends on what you wish to hack. Since hacking is highly illegal, amateur hackers can easily get caught from malicious hacking since they probably can't cover their tracks efficiently enough. I doubt even good hackers can get away with everything, I'm sure they are very careful on picking targets - hacking the White House is not the safest operation to go for.

The effort needed to get into the trade mixed with the high risk of getting caught leads to the fact that being a white hat hacker is a good option for many people who love hacking, they may hack but they leave their contact details and/or instructions on how to fix the problem they caused. So some hackers start hacking as a hobby but end up working for some company they hacked. Security gets improved and the hacker needs to find a new way to get in, creating a loop which solidifies the security all the time.

Hacking the White House might get you employed, think about that for a minute.