What do you mean? That people who mindlessly peruse FB have mush for brains? — baker

No, I mean the sort of physical identity that is of relevance here would be something like, "Having all of a person's the electrons, protons, and neutrons in the exact same relative locations and with the exact same momentums at some instant in time." (Of course not a knowable state, even if a physical possibility, but for the sake of the p-zombie argument - a good enough description of the sort of scenario under consideration.)

So you argue in favor of physicalism?

So you argue in favor of physicalism? — baker

Yes.