What really annoys me about it is that they don't limit the characters in the text box - you can happily paste a novel in there if you want. Just when you go to post, an error that you're over the limit (at least they do say by how much).
It's clear that they use JS on the box (if you don't wait for the page to load, the box won't auto-expand as you type) - why they don't implement a simple script to stop typing beyond the limit is beyond me...
