Extraneous exclamation marks. To use exclamation marks to the point that they are redundant and useless. An example of this would be:
Note that ONE exclamation mark would be sufficient to show that this individual is indeed, laughing out loud.. very loudly. Instead, they decided to add more exclamation marks. Now note how this condition of "extraneous exclamation marks" can actually spread to other users:
ChatUser1 enters the chat room.
: HELLO!!!!!!! :D :D :D
: HEY!!! Wuzzup?!?
: NOTHING!!!!! how r u?
ChatUser3 enters the chat room.
: HEY GUYS!!!!!!!!!!!!
Notice on the entrance of ChatUser1, he/she used "extraneous exclamation marks". Then, so did ChatUser2. Even ChatUser3 was affected before he/she joined the chat room, showing that indeed, "extraneous exclamation marks" are very contagious. Let's watch another occurrence of "extraneous exclamation marks."
: Guess what? I went to the Ford Focus Detroit Electronic Music Fair
: Dude, the Ford Focus
: Well, I only went for the music fair, anyway!!!!
Let's look at this now. "Extraneous exclamation marks" were noticably sparked by something ChatUser2 did not like, which was the Ford Focus. Then of course, we had another example of how it can spread to other users when ChatUser1 replied. Hmmm, very interesting.
So how can we prevent the use of "extraneous exclamation marks"? Well, there really is no solution. It's just another one of those problems that don't really hurt anything but are just plain annoying.