I checked my settings while on vpn on the website panopticlick and while I'm mostly good, my browser fingerprint is "unique".
not that I have anything to hide but I like being private. It's supposed to be a right in the Land of the Free and the Home of the Brave...
I tried turning off javascript through about:config but it just breaks sites-like this one.
If you set the global scope rules then you can block more by default. It's in the upper left, near where the URL is, when you open the menu. The reality is that you'll never have true anonymity online. You can make it more difficult, but even using tools like Tor don't make one completely anonymous - given things like "timing attacks."