1337speak has been quite an interesting part of online culture. It's actually Leetspeak and it means elite speak and was used by hackers and online gamers. It's really grown and evolved into it's very own language with punctuations and grammar as you can see here. The awesome thing about 1337speak is that it can be translated into various forms. For example, "I am the alpha and the omega" can be translated as
1) i 4m t3H 4LPhA 4nD TEh 0meG4
2) i 4M ThE 4lPH4 4Nd +h3 OME94
3) I @M t3h AlPH4 4Nd ThE 0M3G@
4) 1 |\/| 7eH 4LPh4 4|\|d 7eh 0|\/|eG4
and so on and so forth. Here's a tool you can use so you can diss people off in 1337speak.
But for general knowledge, all you need to know is "Y(_)(_)Y(_)(_) pWnz j00" which means YuuYuu owns you which means YuuYuu is better than you ^6^