Add userChrome to Tor Browser to spoof scrollbars to reduce fingerprinting surface
We all know that different systems have different scrollbars. I looked it up right now and Tor browser reports this values for the screen object:
width 1000 height 900 clientWidth 988 (yes I am on Linux)
I found this userChrome ( https://gist.github.com/mrkwatz/277fb19d210a7539304ca2388f24d8e3 ) and it makes the clientWidth become 1000 as intended (you obviously could also make the scrollbars the same width/height as on Windows, but I think this is a better approach). If something like this is included into standard Tor browser it would minimize segregation and thus allow users to use Tor on Linux/Mac while still appearing as Windows users.
Though keep in mind that (for whatever reason) Tor reports different values for the useragent in the HTTP header (Windows) and the JS navigator obj (Linux). This is strange but irrelevant for fingerprinting if the scrollbar thing is not tackled since it is the same result for anyone else. It would get relevant though if Tor applied the custom scrollbars.