brb when I posted my answer, I've been logged out... Anyway it was worded wrongly, I need to stop mechanize from executing the image src attribute. It is web application vulnerability called csrf, where if you have web page : www.guestbook.com/index.php?logout=true, and someone posts on that guestbook <img src="www.guestbook.com/index.php?logout=true"> anyone who views that page will be logged out, and that is what I need to somehow prevent