It's up to you to do your part. I wrote in all caps and got flamed. One important rule is do not shout. Not only is it hard on the eyes, but it conveys anger, frustration. Don't take up space on people's computer screens with frivolous banter.
Normal conversation is fine.
But if you get in there and start writing something stupid over and over, you'll be annoying and get yourself flamed. If you send one, you risk receiving thousands of flames and the cancellation of your account. In the heat of a chat room exchange the last thing you want to do is waste keystrokes typing common sayings. To get around this people have started using acronyms. Those marks are called emoticons or smileys and they are used to convey emotion.