NAS is caused by overexposure to information in the film Johnny Mnemonic .
NAS , also called `` the black shakes '' , is caused by an overexposure to electro-magnetic radiation from all of the technological devices of modern society ( which have become almost omnipresent ) , and is presented as a raging epidemic affecting the world in the future .
Johnny Mnemonic -LRB-film-RRB-