I use the ‘Strict Mode’ in the Privacy and Security menu of Iceweasel. It supposed to block various trackers in all current windows. When it does, a blue shield is displayed on the left side of the URL bar. That’s for the theory.

However, I noticed that visiting the same website with trackers both with Iceweasel on my computer and upstream Firefox on another computer, with this same Strict Mode enabled, doesn’t yield the same result. On my side, nothing is blocked, whereas on the other trackers are. I also deactivated uBlock Origin that is supposed to block these to test a vanilla Iceweasel.

Can someone reproduce that?