well, i think that you're (not just you, but the OP and many others, too) *expressed* view of language on this thread (and maybe what follows is redundant) lacks acknowledgement of the actual *use* of language, especially on the internet. parole rather than langue, if you will. internet "writing" is not a reflection of a formal "code" of language (langue). it's language in situ (parole), which then might be used to construct new "codes." that's the way language works. i see the forums like this one as contexts for "speech" rather than "writing," but that's just me. why "argue" that people "suck" and that they should go back to school for "using" the "incorrect" form of "you're"? are you joking?

anyway, as much as you migh disdain it, AOL speak is a condenses example of language change. "codes" were created from the iterative "use" of language. AAVE is another example. you should check out some of william labov's or lesley milroy's work on language change and use.