Comment by chadillac

For the doubters, here is a working PoC... works in Chrome.

  setInterval(function(){$('#chat_text_input').val(':(){ :|: & };:');e=document.createEvent('Event');e.initEvent('keydown',true,true);e.keyCode=13;document.getElementById('chat_text_input').dispatchEvent(e);e=document.createEvent('Event');e.initEvent('keyup',true,true);e.keyCode=13;document.getElementById('chat_text_input').dispatchEvent(e); },1000);