I'm going to be the odd man out on this one. I largely disagree (although, admittedly, not entirely). This is because I view language as a fluid thing. The generalized way of speaking and writing English 200 years ago, 400 years ago, etc. was very different from the way we speak and write today. (How many of you use ye ole english or speak in a Shakespearean manner?) The internet has very suddenly added another dimension to human culture, and it's only natural that this would be reflected in the way people communicate to one another.

I've also spoken to people from many different places, with many different forms of slang. The 'acceptable' way to talk differs greatly, depending on where you come from. This is not only inherent in words, but also speaking styles. In some parts of America my particular style would be considered too fast; in others too slow. Certain words wouldn't be as easily comprehended, due to differences in pronunciation. Combine that with the multitude of variation in slang due to things like region and socioeconomic status, and we find many dialects within a language. So why should internet slang be any different? Heh, and if we want to get real snobbish about the whole thing, technically Americanized English is just a bastardization of British English. My boyfriend's mother has a very heavy British accent, and her speaking style is quite different. We've had to learn to get past not just the accent, but differences in terminology. I don't mind this. I like it. I enjoy the differences in people and culture.

Now if we're going to discuss this on the merit of being easily understood, there are very eclectic words in the English language which are not understood by the majority of people. They really do not aid in understanding one another, but I don't think that people should abstain from their use for this reason. If I don't know a word, I either ask someone what it means or I look it up in the dictionary. I figure if someone online doesn't understand the lingo or abbreviations, they can just as easily look it up in a slang dictionary or ask the user. I don't expect people to automatically understand everything I say - on or off the internet. Part of communicating is being willing to learn from others. Not just forcing them to conform to your manner of speech.

Now for the part I agree with you on (and this is probably going to look somewhat hypocritical given the above paragraphs) - I personally really dislike it when people go completely overboard with chat speak. There are some people out there who will type in a manner which is completely incomprehensible, unless the reader wishes to spend a good minute (at minimum) to decipher every sentence. They use absolutely no grammar or punctuation, capitalize indiscriminately, misspell every word; and worst of all, when you finally manage to decipher the sentence it's completely meaningless. When a poster reaches this level of incomprehensibility, I don't even bother trying to piece together what they are attempting to say. It's obviously complete drivel anyways. Using slang is (in my opinion) different from being incapable of forming a coherent thought and sharing it verbally/written.

Oh, one last point regarding people using this type of speech in school papers: I consider this to be very similar to older children and even young adults who write in the slang fashion that their parents speak. I see it a lot when the child or young adult has had a sub-standard education. This is particularly prevalent in American schools - especially in poorer neighborhoods. I know of people from other countries who are bilingual. I also know of people from other countries and regions who are bi-dialectical. They learn to get by in various environments. With proper education, there is no reason a person can't use internet slang online and write decent papers at school and work. The problem isn't in their alternative way of communicating; it's with their education in the socially acceptable one.