Do we have to post at least 4 words per post(Or whatever it is) because some silly people such as myself sometimes just post a single smiley as a reply?
The whole 4 word limit thing was put in place mainly because of the number of posts which were simply "LOL" and "LMAO" like Adam says. Though the system isn't perfect at the moment as it can be easily avoided and such.. If the whole 4 word limit thing becomes annoying for people then I'll remove it - but I haven't had any complaints as of yet.
Oh and can people try to stick to the 4 word 'rule' even if you can avoid it by using spaces and new lines - you'll receive a warning and/or your post will be deleted if it's considered to be pointless spam.