Used as an advanced 1337 exclamation mark, it is often adopted by n00bs who need to use it after every sentance they speak. This make said n00bs feel like xtr33m 1337 h4xx0rs, while annoying interwebs veterans.
n00b: ZOMG! I jst pwnd some1 on Everquest!!1!!1!!oneone!!!1!eleven!1!
DJCraigz0rz: I am teh 1337 h4xx0r, i pwn you with my 3lit3 skill0rz!
n00b: 1m g0nn4 g0 NAO!