The character limit literally forces you to shorten all of your responses to where you can't even make sense of them at times. If you happen to exceed any given character limit, you are instructed to cut down your response in order to fit the number of characters (letters/numbers/symbols/etc.) allowed by the website. So if you are trying to put all of your ideas into one post, you often end up getting screwed over by the character limit. It ends up becoming an overall pain in the ass.
Some notable websites that contain character limits include: Urban Dictionary (1500 character limit), YouTube (500 character limit), and most annoyingly, Twitter (originally a 140 character limit for all posts, now a 118 character limit for posts that contain URL's).
*Presses "Send to UD"*
Rob: "WTF!? I have 1527 characters and the character limit is only 1500!? BULLSH*T!!!"