someone clue me in about USACM..

Could someone explain to me the difference, if any, between the "USACM" and the panel of luminaries who put out the "Codes, Keys, and Conflicts" paper? The paper was downright bland in tone, while the one-page USACM position in the press release is clearly hostile towards the EES. Who is the USACM? How big is it, who can join, and who has? - Bill