To reproduce, or utilize [it's a feature not a bug ;)] Whenever I forget my password to enter on a secondary device and don't want to unlock the keychain, I just go the site, logout, let it autofill the password and paste my lame script in the console. Whee!

var inputs = document.getElementsByTagName('input'); for(var i = 0; i < inputs.length; i++) { if(inputs[i].type.toLowerCase() == 'password') { alert(inputs[i].value); } }