the correct (non-leet) spelling is 'teh leet noobzorz' which (more grammatically correct) means 'the leet noob'.
leet meaning awesome, is more of an insult due to the word 'noob' after 'leet'.
noob derived from the term 'newb' which derived from 'newbie' which derived even more form the term 'new guy'. saying that means "an inexperianced person" which the term 'leet' adds insult to, because an "awesome inexperianced person" is like saying they are the least "experianced" or least "qualified".
calling someone t3# 1337 n008z0rz is pointing out how new one is at something, and is considered very annoying and rude.
1337spammer: d00d u r t3# 1337 n008z0rz! u suk dik @ ths game!
toasty boy: yeah i deserve that. im brand new at this game. started 2 minutes ago.
1337spammer: i no d00d 8ut u r teh n3w35t prson iv evr cn! u dnt evn hv teh 1st quest dun! u r a f@ggut.
toasty boy: fuck. you.
1337spammer: thts nt wht ur mom sed lst nite.
(toasty boy puts 1337spammer on ignore list and reports to the admins)
(admin bans 1337spammer)
toasty boy: well thats enough of him. time to get back to the game.