I’m no cryptography expert but I don’t see how they could implement this with true anonymity or without it being spoofed in other browsers. There is currently no way to know with absolute certainty what browser/client web traffic is actually coming from and game anti-cheat devs will probably tell you it’s a nightmare of a problem.

The way I see this working is making it a Mozilla account thing and not a Firefox thing through some sort of stateless cross-origin cookie the sites agree to support. But then, you’re giving up at least some privacy because even if the sites you visit don’t know who you are, you’ll still have to trust that Mozilla is logging anonymized visit counts and that some CEO 5 years from now isn’t going to change that for a quick buck.

Maybe I’m just out of my depth here and someone’s gonna correct me (please do if I’m wrong).