In the akatsuki It seems like everyone but 4 people knew the truth.
Pein, Konan,Itachi, Kisame, Zetsu and Orochimaru knew he was someone else.
Hidan, Kakuzu, Sasori and Deidara were the unknowing 4. They were also the first 4 to die. Were they not important enough to know?
Just back up to...