Just a point of clarity: "CS-Language" such as w00t, 1337, h4x0r5, j00, and other such words you've seen are all part of the unofficial language known as "h4x0r" which in plain english means Hacker. Hacker is a term used to describe someone that is proficiant in several languages of code. Hackers are not the ones that you fear, it's the crackers. Crackers are the ones that commit various acts in a malicious manner. This "h4x0r" language is simply a way that early hackers would communicate without others knowing what was being said...Granted the language has spread and others have learned and even mastered it.

Here's the references I used in my whole 3 minutes of researching :-p
http://www.button.com/cracker_def.html
http://dictionary.reference.com/search?q=Hacker
http://www.google.com/intl/xx-hacker/

[img]i/expressions/beer.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img]

EDIT: Ultrabot has a great link in his above post about the explanation of the h4x0r language.