Submitted by affa in firefox (edited )

And it might cause some javascript not to be blocked. This is how to fix it:


Enable "Expert mode". Then scroll down and disable "Block data URL pages"

HTTPS Everywhere:

Don't block all unencrypted requests

It might conflict with other extensions that modifies CSP response header too. Don't know how to fix compatibility with other extensions.

Test if its working:

Go to a site like

If it shows a ton of information (like mouse movement) its not working. If it shows very little (like IP Address, Country, Latitude & Longitude and just a few other things), its probably working.

More information:



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quandyalaterreux wrote

CanvasBlocker is unnecessary if you have privacy.resistFingerprinting enabled.


NAB wrote

please, do not use ublock, use uBlock origin. uBlock has had a sketchy past.


affa OP wrote (edited )

Oh, I actually meant uMatrix, sorry! I've edited the original post now.

I guess writing when half asleep is a bad idea.


NAB wrote

well I dont really even know what umatrix is then, mind explaining?


affa OP wrote (edited )

Its an extension that let you block certain traffic per domain. You can block cookies, script, etc from 1st party, any 3rd party, specific domains and so on.

Kind of like a firewall in the browser.


NAB wrote

so why not use something like privacy badger instead?