This is more of like chat speak. For those who rather not type a lot and hasten the process of messaging.
Leet speak has the characteristic of numbers replacing letters (I.E. n00b, w1n, 0wn3d, etc.), but isn't limit to only numbers replacing letters.
Example: 7|-|3 [,]|_|1(|< |3|20\/\/|\| |=0>< ]|_|/\/\|?5 0\/3|2 7|-|3 |_42`/ [)06.
Translation: The quick brown fox jumps over the lazy dog
Leet speak:
http://en.wikipedia.org/wiki/Leet