It annoys the hell out of me. Warn them, then ban them is my view.
This is from another forum I use and it is enforced rigidly.
'Why we need to use proper language and spelling.
The following is not mine, it has been slightly altered to fit here, and it speaks to an issue near and dear to my heart which has been nagging me recently...
Since this is a troubleshooting site, the members endevour to impart knowledge to one another. In order to make a clear, unambiguous knowledge transfer a common medium, or protocol, is required. On these forums that medium is generally the following: English.
There are a smattering of other languages as well (not to leave anybody out) but that's the major one. Almost everybody speaks (or attempts) at least two languages and knows how to use a translator for those they don't directly speak themselves.
When a '313373 d00d' uses far too many abbreviations, cool misspellings or leet speak and slang it disrupts this flow of knowledge. Those people here, to whom English is a second language, often use a translator to be able to get a clear understanding of what's actually being said. Thus the fractured, mangled writing used by script kiddes does not translate and these people, our ---- bretheren, are unable to share in that exchange. This is very unfair.
It doesn't matter what base language is used, slang, misspellings and other k-kool and k-rad ways of expression in fact obfuscate the message.
This is why the rule exists and why, if you want to get along with people here, you will follow it. It is not because we are teaching English or are snobs, it's because of simple courtesy to a world-wide audience of highly intelligent volunteers.
Using K-Kool speech does not show how leet and wonderful you are, it instead shows your ignorance and total disregard for others who are using this site to exchange knowledge and ideas. This attitude will only get you isolated and eventually banned as no one will want to answer your questions or deal with bothering to get out their 'leet-boy' decoder rings to figure out what you said. We know what you said, you said:
"I'm an ignorant, selfish, boorish person with nothing useful to impart."
This is a community of intelligent people, if you want to be accepted and take part, then use proper language, spelling and grammar to impart as precise a message as possible. This will allow others to translate your meaning into other languages as easily as possible and to be able to take part in all discussions and enjoy ---- as it is meant to be enjoyed.
Your use of proper language, spelling and grammar shows your intelligence, respect and regard for the other members and makes ---- a more professional and easy to use resource.
I hope this helps to clarify the reasons the rule exists and why you should comply with it.'