However, JonDonym's one - ip-check.info - has an alarming-looking vector down the bottom called 'Browser window'. Even with JS off, this value persists, and reveals even more uniqueness than the 'outer' screen resolution itself can - if you have Firefox's Menu Bar showing, the value changes - if you even zoom in (e.g. use NoSquint add-on on a larger screen), it changes, in fact it's in real-time as you change anything inside Firefox that affects the 'inner' window dimensions itself!
Without using JS, Flash or anything else aside from standard HTML and CSS - does this value get passed onto the webserver and thus can be used as a very serious de-anonymization vector?
Or, being dynamic and CSS, is it only local-browser residing, and so nothing to worry about at all?