re: It might be a chat bot
A good way to prevent automatic "mass posting", which is just like spam, is to have the "clear" and the "post" buttons side-by-side, and their functions randomly reversing. For example on one occasion the "post" button will appear on the right, next time the left button must be clicked to post. The probability that an automatic post-bot will get a message through is cut in half with this method.