I once mentioned it to a classmate that I use GNU/Linux as the only Operating System at home, and he replied in shock, “That’s used by Hackers? Right?” That is true. Almost everyone who calls himself/herself a Hacker uses it, but the fear on his face suggested that he meant to say Crackers. Noooo! Linux users aren’t Crackers. That would be similar to saying that everyone who owns a slide hammer, is a car thief!
Thinking out-of-the-box or using some tool in a way it isn’t meant to be used, just for fun and exploration can be called “hacking”. But try telling someone that you are a hacker, and they would look at you with surprise and suspicion. Because for them, hackers are those who seek for vulnerabilites and exploits in a computer system or a computer network. (whom I call Crackers)
Hacking means exhibiting playful cleverness, which can be using an optical mouse as a barcode scanner, or walking the wrong direction on an escalator. It isn’t even nescessarily related to programming, leave alone breaking into computers.
The term “Hacker” has lost its original meaning. The difference between the two terms is: Hackers make stuff, Crackers break it. All the journalists and writers, please note the difference. You are the main reason of this confusion.
I keep pursuing people to switch to Linux because it is Free and Open Source, but what really made me stick to Linux was the fact that I like to tinker with my system. I like to play around, break stuff, and spend the whole night fixing it. I like to reboot my computer while the system updates are being applied, just to see if that breaks my setup. That’s really what Hacking is all about. (Although the last example was suicidal on my laptop :P, but Hacking doesn’t need to fulfil a purpose. It only needs to be fun :D)
And hacking isn’t only about doing awesome stuff, it is also about sharing it with the community, and collaborating with like minded people. See Hacker ethics.
The hacker culture shares its roots with the Free Software, the Open Source and the Linux culture. These cultures overlap so much, that to much extent, they are the same. [ref] Hackers are the people who provided the backbone to the World Wide Web, as we know it today. They invented Unix. They resurrected the lost principle of sharing and collaborating code. They proved that given enough eyeballs, all bugs are shallow.
Here are a few sources from very influential people in the Hacker community, which inspired this post: Richard Stallman’s post On Hacking Eric Raymond’s How To Become A Hacker and the Wikipedia Article on Hacker subculture.