We’ve been collaborating with Meta on this, because any successful mechanism will need to be actually useful to advertisers, and designing something that Mozilla and Meta are simultaneously happy with is a good indicator we’ve hit the mark.

Oh, truly? Facebook happy with something that somehow respects people's privacy and integrity? Perhaps instead it just shows that Mozilla is slipping. Because they have been, and at this rate it seems like they won't stop. Sad to see.

There is a toggle to turn it off because some people object to advertising irrespective of the privacy properties, and we support people configuring their browser however they choose.

That's not good enough. If this thing needs to be present, the option should be there to toggle on, not off. I don't opt-in to privacy in my bathroom or bedroom, the privacy is mine by default. I don't have to announce to the world that I don't want it peeking in.