First of all anyone to use this phrase is simply worthless. The average teenage AIM user is so lazy they don't have the time to type "haha" in reference to something funny. But now they resort to more desperate measures to be ridiculous they add a "z" to an already terrible phrase. I am assuming it refers to something like LAUGHING OUT LOUD, ZORO, or, LAUGHING OUT LOUD ZEBRA. Which simply translates into I am worthless and should not be alive, and the least I can do for the world is leave.
LOLZ!!!!222 lyKe ii Am SeW wErThAlESZ!7 LOLZ!!!263